Useless extra hertz even more then 60hz is pretty useless. Once you hit about 70-80 frames per second the human eye can no longer see any additional frames beyond that. I really can't even see a difference after about 45 fps. I'd rather spend the money on higher color gamut or higher color accuracy than more than 60hz. Just overclock a 60hz monitor to about 75hz and you are at the limit of human vision. If you claim to see the difference above that its all placebo effect.
The human eye can register different refresh rates and ajust. Play at 144Hz with 3 780s, then go to a 60Hz same res monitor with the same power.