Cleeve, I see clearly where you are coming from, but I have been reading many benchmarks involving both of these graphics cards. To be blunt it is difficult to distinguish the two, different websites will offer different results even on the same benchmarks.
Because they don't use the latest drivers. Half the reviews are still using early 8x.xx nV drivers and CAT 5.11 drivers. Good reviewers are quite consistent.
Plus you yourself Cleeve could be subject to "fanboyism" as you put it, as you have a Radeon X1800XL, a shade poorer than the 1800xt, which our respective OP is planning on buying.
Except for Cleeve has owned, and has recommended ATi and nVidia cards, and has Oc'ed his XL to a point where it would be quite competitive with the XT.
As for your driver comments, I say again, who's name do you see more often on this bug list;http://www.digit-life.com/articles2/digest3d/0206/itogi-video-gallery-bugs.html
Look like they both have issues, and your statements loses credibility there. The driver issue is something from the 90s, it's like basing your current car purchase from perceptions of the MFRs in the 70s. :roll: