mate theres so many more reasons to switch your o.s than just fps.
you get to play dx10+ only games
60 fps at medium dx11 settings is still way better looking than 120 fps on dx9.
think about this...
most games tie there packet data into the fps until a max value is reached. typically 100 for fps/rts games, so even if you get 150+ fps you still only get 100 of the frames updated with accurate information from the data packets. 1 in 3 is a wasted double frame rendered with the packet data of the previous frame.
again wasted performance.
my rule of thumb for my screen is 60hz, 60fps,60 packets at the best quality my card can handle (med high).
there are exceptions to the rules, games like CS which seem to send as many packets as you can get fps which results in a distinct advantage for high fps low ping players but also more ping lag and rubber banding because of dropped packets.
i hope that clarifies what i was getting at.