I don't want to start any religious wars or anything

But, I'm kind of in the same boat as Firebat. Not terribly concerned about "authenticity" (heck, my cabs got a steampunk thing going, so it's about as far from authentic arcade as you can get

)
Anyway, the one thing I have noticed in mame is that if you run on an lcd, you want to run with a pretty powerful graphics card and at the highest resolution possible.
I say this because, to my eyes at least, when you turn on the rendering effects in mame, it does a very nice job of making a CGA image LOOK like it's showing on an old CGA monitor.
I've run Mame on an older laptop with a crap video card, and when mame scales back it's video processing, the results are, oh, shall I say, sub optimal....
But with an ATI radeon x1900, on a Core2 Duo with a dell 24" widescreen, even the vector games look very impressive to me. A purist might balk, but I'll happily tip my hat to the mame team for their results