doesn't really "help your framerates" (unless you are using Vsync), but the higher the refresh rate, the more frames you are actually seeing with your eyes and the longer it will take for you to get a headache from staring at your screen...heheh...personally, I can no longer stand anything below 85Hz anymore. It BURNS! LOL
For gaming purposes, VSync rules...and yet...well...l do not understand why some hardcore gamers (not accusing anyone here, I've seen this behavior elsewhere) insist upon always uncapping the framerate for every game they play, yet have monitor refreshrates of, like, 60Hz or so, so their eyes can only SEE 60FPS out of the 300+ their Uber L337 system is producing.
there is no **** point to having a 312+ FPS if only 85-100FPS or (85Hz or 100Hz at 1024x768) of em are visible!
of course, the real reason they do it is probably so that at lan parties they get lots of jealous people staring at their framerates *sigh*
I have noticed that setting a custom FPS cap that matches or is slightly above your screen refresh rate with a game option of some kind (e.g. the FSO Launcher's flags) seems to work better than using Vertical Sync. Dunno why, it just seems to, sometimes. Then again, I could be just imagining it...