I get decent framerates throught the game, but whever a new ship arrives in game that was not previously there, It'll drop the framrate near to 0, and then be fine again. But this is not always consistent, and usually happens with fighters, not capships. But sometime a new ship will appear and I'll have no slowdown at all. I haven't sone any testing in this regard, but when I have time I'll look into it a bit more to try and give specifics.
Oh yeah, and this is even with the -pcx32 flag turned off. (Which I was using for a while, but now leave off because it chews up some memory and, as you can see, I need all the memory I can get

I only have 384MB RAM)
-pcx32 -jpgtga -htl -fps (-window : used to get memory use)(build 1-20-04)
1024x768
2xAA
4xAniso.
Best Quality (53.03 drivers)
using EAX (Fortissiomo II)
MEMORY VALUES ARE MINUS THE USAGE BEFORE STARTUP (120MB)
-STARTUP -> MAIN HALL:
282 (CPU usage at 80%)
-VISITED TECH ROOM [did not look at a different model] (CPU usage at 100%):
271-EXITED TECH ROOM:
287 (CPU usage at 80%)
-Start Campaing:
490 (Homesick - Capella Capella)
-Committ Mission:
611 (CPU usage ~85-98%)
-Quit mission:
645-Quit FS:
0 (back to 120MB)
Frametrates: (NOT in Window mode)
-Start of mission: Stutering for about 5 seconds then ~50.00
-Turn left to face the massive amounts of ships: 10-12 FSP
-After some jutters and stutters for about 3 seconds, it will go to 25FPS
Now there are

of ships on that mission, so the slow down is understandable. But on another mission I played while I as testing it, the framerates were fine, but then when I turned toward a new group of 4 fighters that emerged from subspace, the framerate dropped down to 0 for about 1/2 second, then then came back up rather quickly. I guess it's loading data from the HD to the page file on my HD since by this point my memory is all used up.
Also, for framerate testing, is there a standard mission you wold want people to look at?
Cheers!