Your Screen Shots show frame rates which A6 at its current stage of development as a general guide to a standard i.e. 50 - 75 fps is now well capable of sustaining in extremely complicated levels.

I have numerous levels of differing sizes and all can sustain those types of frame rates - in most instances for many users 60 - 75 fps is now a consistant reality - given a recent machine spec.

Examples I have would be average of indoor level 5000 portals and up to 400 (yes 400) entities). Outdoor level 16000 portals with as yet small but growing number of entities = all showing 60 - 70 fps.

I am finding that .mdl entities have little bearing on framerate so you can use a lot if needed.

Main frame rate killer seems to be large textures tiled repeatedly increasing portals and wide camera views (panoramas) in outdoor areas. If you design levels well much of this can be avoided. Dont use such textures where they are not necessary and dont let the view show too much at any one given point in a level. (seeing down a long city street as far as the horizon - you cant do that and expect to keep frame rates high) - makes sense though should be stressed if your frame rates are low check these things first.