When it released in late 2020, the Pro X Superlight was a novelty: In a market filled with mice full of holes, the Superlight achieved a weight of just 62 g while retaining a solid shell. The Pro X Superlight went on to become one of Logitech's most successful mice yet, and almost three years later, the Pro X Superlight 2 is attempting to improve on its predecessor even further.

To this end, the Pro X Superlight 2 comes with Logitech's latest sensor, the HERO 2. Featuring a higher maximum CPI, the HERO 2 doesn't perform much differently than the HERO 1 (25K) in practice. Much like the HERO 1, the HERO 2 has no smoothing across the entire CPI range, resulting in significant jitter at higher CPI steps, in turn rendering the highest CPI ranges just as unusable as on the HERO 1. A more meaningful improvement is the ability to finally adjust lift-off distance manually. The HERO 2 still retains some degree of self-adjustment in this regard, but for those cases where this self-calibration results in issues, being able to adjust this manually is most welcome. That said, there have been reports about the "High" setting in particular not working as intended, though I haven't been able to reproduce any issues. General performance is in a good spot on the Pro X Superlight 2. There is no CPI deviation, and tracking is perfectly fine. The same cannot be said about polling stability, however. Whereas 125, 250, and 500 Hz are perfectly stable, 1000 Hz shows frequent 2 ms polls, both in wired and wireless operation. This had already been the case on the Pro X Superlight, which is why it is doubly curious to see this return three years later with zero improvements whatsoever.

Another novelty on the Pro X Superlight 2 are polling rates above 1000 Hz in wireless operation. The wireless dongle turns the Pro X Superlight 2 into a USB high-speed device, allowing up to 4000 Hz polling with the latest firmware, whereas wired is still restricted to USB full-speed and therefore 1000 Hz. Unfortunately, neither 2000 nor 4000 Hz are fully stable on the Pro X Superlight 2. In my testing, the target polling interval of 0.5 and 0.25 ms is generally achieved, but dropped polls are relatively frequent. That is, a wireless packet misses a poll and is pushed to the next one, increasing latency in the process. This is different from packet loss, which equals a loss in data, but undesirable all the same. That said, the latest firmware brings a slight improvement in this regard, as click data no longer is affected by this, only motion. For what it's worth, the wireless dongle used for the Pro X Superlight 2 is much smaller in size than that of competing products such as the Razer HyperPolling Wireless Dongle. As such, it stands to reason that the antenna used in the dongle is smaller, thus resulting in a smaller link budget. Ultimately, this is speculation, but the bottom line is that Logitech's 4000 Hz wireless polling fails to match Razer's 4000 Hz wireless polling in stability.

In terms of motion delay, things are looking better. At 1000 Hz in wireless mode, the Pro X Superlight 2 trails the G403 (control subject) by roughly 0.5 ms, which is excellent. At 2000 Hz, the Pro X Superlight 2 manages to come out ahead of the G403 by 0.4 ms, and that lead is further increased to 0.6 ms at 4000 Hz. Though these numbers are good, they are merely on par with the competition, but not ahead of it. Click latency is excellent on the Pro X Superlight 2. In wireless operation at 1000 Hz, 1.4 ms are averaged, which is a minor improvement over the Pro X Superlight, which achieved 1.7 ms. With the latest firmware, 2000 Hz polling lowers this value to 1.0 ms, whereas 4000 Hz brings it to 0.9 ms, which is the same average achieved at 2000 Hz before the firmware update. In any case, none of these numbers measure up to Razer's click latency at 2000 and 4000 Hz, which sits at 0.6 and 0.5 ms, respectively, and the ASUS ROG Harpe Ace Aim Lab Edition even manages to beat the Pro X Superlight 2 at 1000 Hz, averaging 0.8 ms. For the record, there is no difference in click latency between the "hybrid" and "optical only" switch configuration settings, which is why opting for the former for higher battery life is recommended.

Of course, both 2000 and 4000 Hz come at a price, which is reduced battery life. At 1000 Hz, Logitech cites a battery life of close to 100 hours, which is cut almost in half by enabling 2000 Hz. Around 50 hours are still formidable, though not any better than what the Razer Viper V2 Pro is able to muster at 2000 Hz as well. Charging is reasonably fast on the Pro X Superlight 2, but due to how stiff the charging cable is, playing while charging isn't the most pleasant experience. Thankfully, one of the most worthwhile improvements of the Pro X Superlight 2 comes into play here, as USB Type-C connectivity is finally on board, allowing one to use a more flexible third-party Type-C cable instead. The ability to monitor the current battery charge level is somewhat limited on the Pro X Superlight 2. The software does include a percentage-based indicator, but since Logitech decided to not implement a fuel gauge IC, the readings aren't particularly reliable or accurate. During testing, I've found the reading to suddenly sit at 60% after turning the mouse off and on again, which is undoubtedly false, as the charging current was virtually nonexistent at this point.

In general, GHUB isn't what I would call a particularly good piece of software. There is the odd bug, such as the maximum CPI value being impossible to set by dragging the slider to the right, returning random values slightly below the maximum instead, and resource usage is substantial. The UI is also needlessly convoluted, as lift-off distance adjustment, for instance, only becomes available when checking the "advanced" box, and when doing so, the CPI values don't match the previously set ones, which may be another bug. Thankfully, the Pro X Superlight 2 is compatible with Logitech's Onboard Memory Manager, which has almost the same amount of options at a fraction of the resource cost. When adjusting settings in GHUB, any changes are first saved to a software profile, which then can be saved to the onboard memory, but not directly edited in GHUB afterwards. This is somewhat backwards when compared to mouse software from most other manufacturers, where any setting changes are saved to the onboard memory right away. In GHUB, you'd have to disable onboard memory mode first, then change what you want to change, then enable onboard memory mode, and save the changed profile to onboard memory again. Hence, simply sticking to the Onboard Memory Manager is much easier, as you can edit everything directly there, though some settings are completely absent, such as the switch configuration between "hybrid" and "optical only" mode, and whether such settings are retained without GHUB is something I haven't been able to determine. For what it's worth, I also find it odd that the Pro X Superlight 2 lacks a 400 CPI step out-of-the-box.

Instead of the trusty Omron D2FC-F-7N switches used on the Pro X Superlight, Logitech has opted for their so-called "Lightforce" switches on the Pro X Superlight 2, which in fact are Omron D2FP-FH1. Being optical switches, the main benefit of these is their inability to ever develop unintentional double-clicking due to wear and tear. While this sounds good on paper, these switches don't fare very well in practice. The main issue with the clicks is their inconsistency. While certainly on the stiffer side of things, the right click feels fine on my copy, some pre-travel notwithstanding. The left click, on the other hand, feels dull and muted to where one may be inclined to call it faulty. In addition, it emits a rather irritating "ping" noise upon actuation, which further adds to the unpleasant sensation when clicking. How this switch ever made it past QC, I do not know, but as a customer, one can't do much aside from drawing the RMA card and hoping for better luck next time. Frankly, I'm a bit baffled experiencing such stiff and inconsistent main buttons on the successor of a mouse known for its light, spammable, and consistent clicks. I've previously had some experience with an earlier revision of this switch on two releases from Corsair (M65 Ultra, wired and wireless), which likewise exhibited a greater than average degree of inconsistency between the left and right main buttons. Eventually, Corsair decided to switch off this switch model, and instead opted for optical switches from TTC, which didn't necessarily feel better but were much more consistent. In any case, even if one gets a perfect set of switches, those fond of the light clicks of the Pro X Superlight will inevitably be disappointed.

The side buttons have never been a strong suit of the Pro X Superlight, and sadly, this continues to be the case on the Pro X Superlight 2. Since both the surface-mounted Omron switches and side-button construction are unchanged compared to the Pro X Superlight, it comes as no surprise that the side buttons aren't improved one bit, and any reports of the contrary can be chalked up to unit-to-unit variance. On my unit, the forward button is quite decent at least, as pre and post-travel are under control, but the back button has noticeable pre and post-travel, actuation is far from even, and button response is somehow both overly sensitive and terribly mushy at the same time. Given the wide criticism of the side buttons of the Pro X Superlight, I'm quite stunned to see zero improvement in this regard. No changes have been made to the scroll wheel encoder as well, which continues to be a TTC "Silver" (white) encoder. Yet, when comparing scrolling directly between the Pro X Superlight and Pro X Superlight 2, I can't help but notice that the scroll wheel on my extensively used Pro X Superlight feels quite a bit better than that of the freshly unboxed Pro X Superlight 2. Tactility is better, the individual steps are more well-defined, and noise levels are similarly high, whereas scrolling on the Pro X Superlight 2 feels lighter and less controlled. Apparently, the encoder is more lubed on the Pro X Superlight 2, leading to less tactile scrolling, which is a clear downgrade in my book. The scroll wheel switch isn't exactly great, either. Travel is weirdly low, yet actuation somewhat stiff and noticeably dull. The wheel click on the Pro X Superlight wasn't much better, but if anything I would expect an improvement in this regard, yet the opposite is true.

To accommodate the higher polling rate and inclusion of optical switches, the battery capacity has been increased slightly on the Pro X Superlight 2, from 240 mAh to 290 mAh. Despite this, the Pro X Superlight 2 ends up weighing 58 g, which is 4 g less than the Pro X Superlight, and enough to achieve parity with the Razer Viper V2 Pro, though the latter does have a CPI button at the bottom, which the Pro X Superlight 2 still lacks. Build quality is largely on the same high level as on the Pro X Superlight. On my sample, there is no rattle when shaking, applying lateral pressure results in some creaking but no flexing of the shell, and actuating the side buttons by pressing below them is impossible. What hasn't changed much, however, are the mouse feet, which is rather unfortunate. Logitech advertises the feet as being additive-free PTFE, which they very well may be, but due to how thin they are and how lackluster the rounding of the edges is, glide isn't exactly stellar. Replacing the feet therefore may be desirable, but doing so is made needlessly cumbersome by a rather curious design choice by Logitech. Compared to the Pro X Superlight, the shape of the bottom skate has changed, which serves little purpose other than rendering all existing third-party replacement sets incompatible with the Pro X Superlight 2. Hence, Pro X Superlight users sitting on leftover sets need to buy new ones if they intend to switch to the Pro X Superlight 2.

Overall, the Pro X Superlight 2 is not a bad mouse, and if it were to exist by itself, it might even get our Recommended award. However, with the Pro X Superlight still being available, I have a very hard time making a case for the Pro X Superlight 2. The Pro X Superlight has much better main buttons, a potentially better scroll wheel, better scroll wheel click, weighs basically the same, has virtually the same battery life at 1000 Hz, performs almost the same, but can often be had for $100 or under. The only thing the Pro X Superlight 2 has going for it are USB Type-C charging and double-clicking on the main buttons being impossible. In my book, this isn't enough to justify paying $159, and when looking at the competition from Razer and others, the Pro X Superlight 2 becomes an even tougher sell. The Razer Viper V2 Pro with the HyperPolling Wireless Dongle, for instance, has everything the Pro X Superlight 2 has and more, and has had it for more than one and a half years. Accordingly, for those that already have the Pro X Superlight, getting the Pro X Superlight 2 makes little to no sense, and for those who don't, there are other, better alternatives from competitors, be it Razer, VAXEE, ASUS, or LAMZU, especially when one considers that those $159 don't even get one good quality mouse feet or a flexible charging cable. As such, I can't recommend the Pro X Superlight 2.