I don't remember which version it was that they added RAVE support, but it's worth checking out.
It stretches to fit the screen, and blurs the edges of the pixels.
There was almost no performance loss on my G3/300 B&W, and the picture looked tons better.
I found there was a RAVE pluggin on 0.36a. Not sure how it works or what it does but I dropped it from the MAME 0.36a Pluggin folder into my extensions.
Now what I did next, I'm not sure if I could have done the same thing before I added the RAVE extension.
I found I could get Ms Pacman and various other games to display full screen in cocktail mode, 2 different ways. Either set the MAME video at 3 X 3 and the monitor/screen at 1024x768 75hz.
Or set at 2 X 2 and 640x480 117 hz.
The 3 X 3 settings is better when not running MAME so I'm sticking with that.
I am psyched!
I'm leaning towards getting a Mag-Stik Plus Ball-Top but...