the two types of monitors use different lcd panels, I personally dont feel its worth it unless you make a living from it. for gaming the tn panels are much faster and average from 1ms to 5ms depending on the monitor. my son has a Dell with the good panel, and I cant really see much difference between his and mine. i am using mine out of the box, his has a little better color richness, but if i adjusted the color on mine, im sure it would look as good. his was more than three hundred dollars more than mine, but it has a card reader and usb port built in.
I dont think the refresh rate matters unless you have a 3D monitor or use 3D glasses. If it was so great there would be more of them available, it is not a new tech.