Oh, and I looked at the 9600XT, but I couldn't consistently find whether it was 4-pixel or 8-pixel architecture. Some sites actually said it was both.

It appears, then, that either many places have messed up info about their products, or that there are actually several "trim packages" between cards with the same chipsets. I've now found literally dozens of cards with the GeForce 6600 (not GT) chipset that show variations in memory and core clock speeds.
So it looks like it's coming down to either the Radeon 9800 PRO at ~$125 or the GeForce 6600 at ~$135. Not what I wanted to spend, but I also don't want to be wanting a new card in 2 years, and 20-30 bucks over isn't too bad.
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The Unpronounceable Krsqk
"Well, sir, at the moment my left processor doesn't know what my right is doing." -
Freefall