6800 OC != 6800 GT
If you're gonna get a 6800 (ie. the NON GT version), just get a 6600 GT. They work out to about the same. Yes, 256 mb is worth it IMO. However, 512 mb is not. If both prices are in U.S. dollars, grab the 6800 Ultra. If the XT is in Can. $, then I'd go for the Ultra (works out to about $400 Can at the most), but would still consider the XT a good deal. I consider CAD, SM3.0, and Linux drivers to be more important. If you consider movie playback and cost paramount, however, go with the XT.
Basically, you'll know what to do.
