not shur, except for what i can see, and i would guess...
)the monitor prolly consumes more power the higher the rate
)i set my monitor at 144hrz just for a few minutes while i played a FPS game(just to see what it was like) and its soo smooth and quick that u prolly dont need Vsync at that speed, and theres no noticable flickering.
)i have my montior at 56hrz most of the time, cause i dont need any speed for just web surfing or photoshop or whatnot, isnt afected.