Uglok, did you do a clean format upgrade or let 2k install over WinME, b/c win2k shld not run a game slower at all, so something is wrong there.
dfusion, is your 2.6 P4 a 533 FSB w/ DDR333 RAM? Depending on which P4 mainboard chipset you have could affect your FPS by a good 20 on average. Did you build the PC or buy it prebuilt, Im just curious which mobo you have and what speed RAM.
I have an nforce2 w/ 1.7 gig OCd to 2.23x333FSB- w/ a g3ti500 that gives me min 40 FPS in worst case situations, but spikes up to 250 in hallways.
ET and RTCW are modified quake3 Team Arena engine based game, not vanilla q3 engine. Team Arena ran like a dog too, just part of the sacrifice of tweaking the engine to work w/ large outdoor maps.
I didnt vote in the poll b/c I disagree w/ your wording. If you play on PB servers, alot of speed tweaks in CFG may be disallowed. Those options are tweaked by server admins, which moots an SD written speed CFG. I also do not believe it is possible to CFG tweak this game to run an avg of 20fps faster.
What would be interesting is to know the system specs of SD guys and what settings they preferred. Id be willing to bet most SD guys arent running the latest greatest hardware, coders are fussy about stability - very quirky I think : )