Some areas that need to be optimised or reviewed:

My rig:
SSD HDD
16GB memory
i4670k @ 3.4
nvidia gtx 760

I used mat_leafvis 1; mat_wireframe 3

Testing done without players/bots
- FPS glitch, drop of 100+fps when transitioning between vis leaves outside B doors, it's momentary but there's a noticeable glitch (freeze)
- Outside areas have poor frame rate without players or bots, around 150, when I get 250+ indoors. A lot of hidden areas are being rendered, which lets me to believe that the walls are all func_detail or models.
- FPS glitches in various places outside around the walls when moving, FPS varies between 120 - 230
- FPS glitches at CT mid, frame rate drops to around 100 in some angles
- Blocking walls not blocking vis leaves
- Door to mid doesn't use a func_portal, since elements behind it can be rendered
- Vis leaves need to be cut at B door stairs, since many elements are being rendered that shouldn't be, half the reason why there's an fps glitch
- T corridor up has bad frame rate occasionally dropping to 100
- FPS glitch when moving through vis leave at top of mid to T corridor up
- vis leave splits needed at T start when moving towards top of mid stairs
- fps glitches in various areas in T spawn when looking towards A site and parts of the large adjacent building become visible
- fps drops to 100 and below at T side upper/T start doorway, sometimes a glitch too, depending on the angle and direction facing
- some dicey frame rates inside connector, might be that the glass is transparent and renders more than the player can see

Tested with bots
- Virtually unplayable in the outer areas with significant frame rate drops to 50fps and lower. This is against bots using up cpu processing, but there are frame rate drops.