Hey all,
Just thought I'd pass along a gem...
I've recently purchased an AGP Radeon X1950 Pro (a Sapphire unit, little over 100GBP from aria.co.uk), and it is frankly "da bomb!"
Plays FS2004 at full without any problems locked at 30fps at full res for my monitor (1680x1050) which my old card (nVidia 6800GT) couldn't, it'll play BattleField 2142 at that res on full without dropping frames, but now the great news, it's running FSX at full res at sensible settings (medium high for everything was no worse than my old card in FS2004 at full)!
It's still not going to make me register my FSX install as I only wanted to test it on my old card, where it was horrendous, and I've got my new PC come post Xmas anyhow which should let me monster FSX but if you're "stuck" with AGP, I can heartily recommend this technology.