I have not experienced any noticeable in FPS since 1.1.3 If you can post your system spec including graphics card, OS X version etc.As for me, my framerate has dropped to almost 0 on many occassions since the latest patch (1.1.3). This never happened to me before ever...
I lowered the graphics to their lowest settings...same issue.
My game is still crashing due to a memory leak from time to time.
I read in their "Mac Known Issues" section that the framerate issue is caused by people with 4GB or RAM or lower...I have 8GB installed.