Visually the most important feature of the ASUS GTX 580 Direct CU II is its huge cooler that occupies three slots in your system. Yes, three slots. ASUS promises that this will add more cooling capability to their beast, so the card can run cooler and quieter. We have heard that promise in the past for triple slot cards and it didn't work out every time. First of all I have to praise ASUS for making the bold move of bringing a card to the market that requires three slots. In our testing the noise levels of the ASUS GTX 580 Direct CU II are simply amazing. After lots of complaints about the GTX 480's fan noise, NVIDIA already put a lot of effort into quietening their GTX 580 reference board, and they did well. However, the ASUS GTX 580 DCU2 is a lot quieter than that. Its idle fan noise is in the neighbourhood of other "quiet" cards from all performance ranges, so that's good already if you are planning on doing a lot of desktop work. Under load the card's fan noise is outstanding. It is quieter than most mid-range cards but can still deliver a massive performance punch being able to handle anything you can throw at any single monitor setup.
ASUS has applied a small factory overclock on their card, which is probably limited by NVIDIA policy. This increase results in about 1% extra performance, something you won't notice in every day gaming. Manual overclocking yielded a dissapointing 827 MHz, we heard other colleagues got better results on their review boards, so this might just be me getting a card that doesn't overclock as well. In the hands of a pro with LN2 cooling, we have seen well over 1500 MHz GPU clock. Our voltage scaling testing supports that the card has really a lot more potential than what can be easily reached without extensive mods and complex cooling.
ASUS has also improved on the display connectivity options by providing full-size HDMI and DisplayPort connectors instead of the single mini-HDMI on the reference board. However, you are still limited to two active display outputs due to NVIDIA's GPU design. Another small point worth mentioning is that the card consumes less power than the NVIDIA reference GTX 580 - even though it's running higher clocks. This is more evidence that ASUS did a good job at re-engineering the GTX 580 design to fit their needs.
Last but not least, the good news is that ASUS will only ask a $5 price premium for their GTX 580 Direct CU II over other NVIDIA reference design based boards. So the bottom line is, if you plan on investing into a single powerful GTX 580 card that will last you for a few years and don't plan on using SLI (or have a board with triple slot spacing between the PCI-E slots) then the ASUS GTX 580 Direct CU II is the best card you can get. Trust me, the low noise makes a huge difference. On the other hand, if you are planning to most certainly upgrade to SLI at a later point, possible triple or quad SLI, then you should consider going with a dual-slot card, so you won't run into space issues later.