There are also disadvantages to 120hz monitors, they can appear washed out, less vivid and colour accuracy is not as good as say an IPS panel at 60Hz.
This is pretty much true for TN v IPS regardless of the refresh rate.
One of the best (once calibrated) 6bit TN panels for deep colors is infact the Samsung 2233rz (120Hz) - really missing that panel at the moment as this BenQ XL2420T just isn't a patch on it image quality wise but couldn't go back to the lower resolution now.
Seriously can't wait til Samsung do a new line of 120Hz panels without the issues plaguing their current ones as none of the current alternatives I'm that happy with and the Samsungs look great (as far as TN goes) but I can't be dealing with the displayport issues, etc.