Lots of threads about issues with GM. But I just wanted to say how happy I am with GM and how it looks on my monitor.
My system is what I call a Mame Cabinet on the cheap.
Cabinet is a NFL Blitz 4 player, removed all the guts, as the joysticks are 48 way.
Converted it to Jamma, installed a jpac.
Monitor is the original, jumpered to 15Khz from 25K
Computer is a old AMD running at 2G with 2G of Ram.
Video card is an Nvidia...

After reading the GM forums, I bought a ATI 4350 locally off of Craigslist for $40, installed GM and I love the results! Looks like an arcade game should!
I do have an issue with tall games, but I'm going to change the 288 to 256 as recommend in other posts.
Can run all the latest games, but the 80's classics play great.
Damon