The latest patch didn´t cause any FPS issue for me, too. Instead I was able to do some tweaks and turn up some settings and still have around 30 to 40 FPS.
Unfortunately another problem has arisen which happened twice to me. I use a laptop to play games etc. and after playing yesterday and today it completely shut down after rounds end. The screen simply goes black, my laptop shuts completely down and I have to restart it.
It´s rather strange and I fear that something might be broken or will break if this´ll continue. It´s odd since it happened at rounds end when the server was about to switch maps. Does someone have a clue what that might mean?