Ye some maps, in fact too many maps have this issue.
People probably lower too many graphics when they dont need to but these will improve things considerably..
screen res = 800 width or so
cg_marks 0
cg_drawgun 0
cg_detailedtextures 0 (or maybe detailtextures?)
r_lodbias 2
do a vid_restart and play for a few mins before checking to see if theres an improvement. Better still, try it after quitting the game but ensure these are set before playing
It's not actually lower fps that causes this problem as you might have guessed, it's the change when it drops 40 fps when jumping then rises again. Might be worth trying com_maxfps 87 - this is certainly better than a changing fps if the maxfps is 125.
And no, not everyone likes this map.. i hate it
I used to like it until I played it for too long maybe and just see it on too many servers. It's a great map for learning on though.
18-25 fps? wow.. thats a challenge and a half
I wonder if pmove_fixed is default as 1 on the servers.. cos if its not then it would become impossible to hit or do anything.. and you just shoot things by accident
make sure cg_pmove_fixed = 1 on the client. That should compensate for loss in speed when fps changes. A good indication that its off is that when you jump you feel it kinda bouncy and dont seem to go forward much.
pmove_fixed isnt perfect though. It's network dependant so I think you need cl_maxpackets 125 for it to be effective.