I can easily spot the difference between 60 and 90 in mouse response - 60 feels horribly slow in any game where mouse controls camera. Visuals, not sure, never really tested it - in that UFO test I can easily spot the difference, but in real gaming it's the responsiveness that is most noticeable for me.
With gamepad, I always lock to 60fps - I don't play anything that requires precise aiming with gamepad, so everything else benefits (from my POV) from locked 60fps and higher visual settings instead of pure frame rate.







