IPS is superior for sure. On my desk you'll find a high quality LED screen (22.5 inch) and a cheaper IPS screen (22 inch). Both have a resolution of 1920x1080. You wouldn't think the difference would be that big, but it really is.
However, after disabling refresh rates that do not apply to your monitor in Windows, I don't have the option to go to 120Hz though. Still, the difference is very noticeable at lower refresh rates, so it would be safe to assume it is even better at 120Hz.