There's a lotta youtube stars .... almost all nondeserving. As for AIOs having "better temps", it's a myth ... I have yet to see that. At leat no AIO I have seen performs better and matches the noise level of a comparably priced air cooler. The H100i for example is **12 times louder** than the Noctua ... See 17:12 mark **
And now we have several coolers < $50 that perform the same or better than those $90 air coolers above (Scythe Mugen Max @ $37 and Fuma @ $45 for example)
One reason you see what you see is sponsorships ... the "why anyone would sponsor athois guy" (Jayz) who drills holes thru his motherboard is beyond me. He'd be a great addition as the tech guy on Fox. CLCs might as well be called "Faux Water Cooling". The idea of a aluminum rad and copper block is something that should never have been adopted. You can clean an air cooler with compressed air ... but with corrosion inhibitors having a useful life of 18-24 months you can not clean this ....
https://martinsliquidlab.wordpress.com/2012/01/24/corrosion-explored/
If ya want a "gateway" into custom water cooling, then by all means buy an AIO that is **NOT a CLC** such as those from Swiftech or EK ... when ready to move to a custom loop, you just add a GPU Block, MoBo Block, reservoir. extra rads or whatever ya want without needing to replace anything. Also, one of the most common mistakes AIO users make is installing their fans backwards based upon the faulty logic that blowing the air up out of the case is a good thing. Yeah we all learned in 8th grade earth science that hot air rises but that's not the issue here.
What happen in your typical 5 fan mid tower case is the user winds up with two front fans blowing in with their air flow restricted (by up to 30%) by intakle air filers. With the two or three fans on top blowing out, and the rear blowing out, you have a very significant negative pressure situation which many dismiss as a dust problem of little significance. That's not the big worry... When installed correctly, in accordance with Corsair's AIO instructions, the rad fans blow in using cool exterior case air to cool the coolant. The faulty thinking is "ooh that's a bad thing cause you are pushing hot air inside the case". And you are... where with 4-5 fans blowing in, the positive air pressure immediately expels thru the rear fan and rear case grilles. You don't ned to match intake an exchause fans. we don't do that when ventilating buildings, cars, power plants, kitchens. etc cause it's not necessary.
When AIO rad fans are blowing air out, you are expelling the 90 - 130 watts of heat generated by your Intel CPU out the top... and as a result of 3-4 fans blowing air out and two significantly flow retsricted front intake fans blowing in, the significant negative pressure is sucking lots of air in from outside the case thru those rear case grilles ... yeah, the ones right above your 250 watt GFX card and 650 watt PSU. So what' the point of expelling the heat from the 90-135 watt CPU if you are sucking all that 250 watt GPU / 650 watt PSU hot exhaust right back in thru rear of case ? And yes, you can easily "do this at home" with a $34 Chauvet Fog Machine.
We only build air, custom loops, OLC type AIOs (Swiftech / EK) with all copper (or all aluminum for the budget conscious) componentry. With Intel, I haven't hit the thermal limit with a single build since Haswell ... As long as the purpose of your build is not to run synthetic stress test programs, have been able to consistently hit desired OC without hitting the temerture wall; if anythig it's a voltage wall that holds things back. Under stress test @ 4.7 - 5.0 Ghz, RoG Real Bench doesn't hit 80 and we are near 1.5 volts (w/ AVX) when we get that high. CPU temps are in 70s ...and drop to high 50s / low 60s worse case when doing anything else. GPU temps, eve in SLI range from 39 @ 1200 rpm fan speeds to 44 with < 850 rpm fan speeds under stress test ...450 - 650 fan rpm in gaming.
For me water cooling is all about quiet ... not being able to hear the fans or even tell whether the system is on or off when ya close ya eyes. With Corsair 100i for example, I'd need 30 foot KB, mouse and monitor cables cause the box would have to be in another room .... see 1:15 mark in video below
https://martinsliquidlab.wordpress.com/2013/03/12/swiftech-h220-vs-corsair-h100i-noise-testing/