I'm also trying to force refresh rate on Doom 3 because I get tearing more when it is locked at 60. THERE is a difference between higher refreshrate and lower. I remember on my CRT monitor, before the refreshrate was upped the frames were hitting 36 min, and after i changed the refresh to that monitor's max 89hz, it was hitting at lowest 48. SO, imo that is a big difference.
For those of you who might say "you can't see the diff" "Fraps says YOU CAN"