Forcing dxlevel to 81 solves many issues regarding abuse of flashbangs. It puts the game at a more even playing field which is why the European leagues have enforced it for so long.

Dxlevel 95 and above basically make it so you barely get flashed, or you get flashed for a very minor period, depending on which gfx card you're running (ati vs nvidia). Ambient occlusion is also another huge issue.

Also, you can proxy into any server using a tunnel, it just re-routes your connection from another location and causes huge ping spikes which is why most idiots don't try it. It is still possible.