I bought a KN8 Ultra maybe a month ago. I'm not planning to overclock it, or maybe only slightly just for grins. I put a 3200+ (Venice) and an eVGA 6600 on it. So far I've been very satisfied, although I'm not a hardcore gamer (I do play a lot of Guild Wars, but not FPS). It has 4 DDR slots (2 used now), 4 SATA ports, and I forget how many extra USB headers, but more than I need (8?), not counting 4 USB ports in the back.
The only glitch I've found is that the extra fan I put in the back isn't reporting its speed even though it has a 3-pin connector. I suspect that's most likely the fan. It may be that only only the front fan header gets reported; I've not dug into it yet.