4k marks isnt bad for agp, what games are you currently playing.
Right now, I'm playing demos to get a feel of what this card can do. All games are on max settings (except Crysis demo).
Company of Heroes demo seems to average close to 30 FPS but when you zoom in and pan the camera, it drops to single digits. Sacred demo stays locked at 60 FPS on default camera but when you zoom out it drops to 30 FPS and in town it gets close to 20 FPS.
Games that seem to average 30+ fps include Doom 3 demo, CoD 4 demo, CoD UO demo, Titan Quest demo, Quake 4 demo. Crysis demo averages 30+ FPS on low settings and about 10-12 FPS on the Very High XP hack. (Until it hangs and quits running)
Games that run at a constant 30+ FPS include Dungeon Siege II demo, Far Cry demo, CoD 1&2 demos, Hitman 2 demo, F.E.A.R. demo, Jedi Knight: Jedi Outcast demo, Battlefield 2 demo, Republic Commando demo, Transformers: The Game demo. Half Life 2 demo gets incredible FPS at constant 30+ FPS and gets into triple digits because it is optimized for ATI drivers.
This GPU really masters older games like Jedi Outcast and Hitman 2 (constant 60+ FPS) with my P4. Max Payne 2 demo is almost always at 60 FPS, Freedom Fighters demo is locked at 85 FPS. CoD 4 runs surprisingly well considering the CPU bottleneck. My sound card is very good also and helps a lot with FPS performance.
This is the best AGP card you can buy and it is better than the ATI 4xxx series GPUs that are coming out for AGP in benchmark tests, so get this if you have AGP and don't want to full system upgrade but know that your CPU will hold you back if it isn't a dual core.