hehe
well if those little slots on the back of your case are valuble space then the fact that the 6800 takes up two as apposed to the X800 which only needs one that may be a viable concern.
Just so ya know. Both cards use one "agp/pci" slot but the Geforce card takes up two spaces on the back of the case as far as PCI "card holders" if you will, go. On the case itself, not on the Mobo.
There are some down sides to the 6800 Ultra as far as power goes. What are they? Well, its' demands. Minimum req for the 6800 is 450w. Thats minimum. Recomended is far beyond that. And yes, it does take up two power leads. So if power is a concern the 6800 may pose a few problems for you. Neither of the two cards are for a person looking for great performance at a low price; the 6800 even more so. At close to 600 dollars its nothing short of being over the top in price. The most expensive isn't always the best, but in this case, in my position, it is.