Higher is definitely better, though I was under the impression that all non-CRT monitors nowadays are either 60hz or 120hz (the latter being high end and pretty expensive monitors, quite recent too). Unless it says in windows that it's running at 75hz then I'm afraid it probably isn't really, even if games give the option!
You'll need to make sure you're hitting 75fps for the smoothness and gains of actually using 75hz.