I've confirmed that Samsung 245BW monitors run games at any refresh rate you can think of with Groovymame + Powerstrip. It's pretty fantastic.
Pacman (60.60), Rtype (55), MK (54), Neogeo (59) etc. all ran perfectly with no tearing/hitching.
Combine this with HLSL, and you have a legitimate alternative to a CRT. This is amazing.
THANK YOU Calamity for making such an awesome MAME variant. This really blows open the doors for what's possible in an arcade setup.