The truth is not fanboyism.
The XTPE was a bit faster than the Ultra. Score one for ATI, at $500.
Not long after launch, when only the 6800GT and X800P appeared in any significant numbers, nV's drivers led to the GT outpacing the Pro. So, nV led at the $400 mark.
The 6800 kicked butt at $300, mainly because its only competition was the year-old 9800 series.
The 6600GT also was superior at $200 for several months.
Now, ATI is price and performance competitive across basically the whole range (X800, XL, XT, that crazy AGP AIW XT for a while)--but they're still missing the SM2++/HDR in the GF6 that allows for exclusive effects on a handful of pretty well known titles. So, let's call it pretty close to a draw. ATI has at least rebalanced the playing field....
.... up til the GTX, for which they are without an answer for another few months. Yeah, they seem to be in a better position than they were last year, and their upcoming line-up should bring them up to speed in all areas, but I'd say there's certainly been opportunity aplenty to lose fans.
I don't think this is bashing ATI, it's just pointing out the obvious as it relates to 3D gaming's two biggest features: speed and special effects. Power draw, heatsink size, noise, etc. are all of secondary importance for the majority of the market, IMO, and only really become important when the primary playing field levels.
Edit: geo, hope summers eternal.