the engne is running on my test pc (P400 and a radeon9700pro) and a framerate of ~30-40 with about 120.000 visible triangles at a time. Allthough it depends how many and how big textures you use.

90.000 tris with high quality textures
and almost 200.000 with standard to low poly textures.
Animated vertices cost also some time (not much but anyway)

so you should be able to use about 120.000 - 140.000 triangles for a game with a6 (more with better gfx cards and cpus).

Testing my testlevel with almost 700.000 faces on a P4 prescott with a 9800pro got me about 45-60 fps (with applied template codes and player movement/weapons)...all in 1024/768/32.

updating to the newest ati betadriver i got alomst +30% speed in every game and gs as well.

A6 is pretty fast, but has some major break points that slow the engine:
1.) huge textures and lots of them reloading often is kolling every standard gfx card and escpecially gs levels.
2.) terrian renders as hell on my system (100.000 textured faces for a terrain doesnt bother my card) but the fact that a transistion system is missing for a smooth terrain transformation from lowpoly to highpoly (just entire culling is avaible) makes hmps a bit of a problem for fps games. Its simply useless to see all 50.000 faces of a mountain that is far back on the screen...that slows down a lot.
3.) particles....dont know why but gs hates particles in huge ammount and with alpha maps (like every engine)...but gs cant stand them especially
4.) models run thru the engine very smooth and even highpoly is rendered fast and nice...only thing to think of here is skin size (might change if mulitlayers are avaible)

in general: use every LOD method and clipping possibility you get...simply skin changing and leveldesigning can be a wonder for a good fps.

a nice benchmark level with terrain, enemies, a level complex and shaders would be nice for A6.