Just thought I'd wrap up my experience with GameVE. I decided to keep mine and take GameVE's offered $20 credit.
As for my impressions of the FX 5800 Ultra, I think it's a very good card. It's been rock-stable with every game I've thrown at it (NeverWinter Nights, Jedi Knight II, the 'Tenebrae' version of Quake, Diablo II, StarCraft, Warcraft III, Tiger Woods 2003). I've been getting around 95 FPS in Jedi Knight II (1152x864x32) with 4x aniso and 4xS antialiasing, on an Athlon XP 1800+ and a KT266A mobo.
If you haven't checked out 'Tenebrae' Quake and have either a Geforce 4 or FX, I highly recommend you take a look. It's basically a "mod" that adds Doom III-type pixel lighting and stencil shadows, etc. (Sheesh, I sound like a friggin' ad, sorry.)