MacMame is pretty awesome, actually. The only problem I have with it is the aforementioned romset compatibility issues. Because of this I have a couple different versions and I alternate between them depending on what game I want to play.

I've actually noticed that MAME is getting better. About half of the sounds from Donkey Kong and Donkey Kong Jr. were not emulated in prior versions but now are.

I remember there was a thread here linking to an article about a year ago where people were upset about some of the philosophy driving the MAME developers. Specifically, there was an update of MAME a couple years ago that eliminated the feature to save high scores. The developers justified this stating that this more accurately simulated the "real experience" of using the arcade hardware because all the high scores would reset when you unplugged the machine. It is kind of BS imo, but hell, they're providing me with hours of free entertainment, nostalgia, and enrichment of my knowledge about gaming, so I'm not going to complain too much.

This thread is starting to remind me of all the harsh criticism I'm reading levelled at the Angry Video Game Nerd, and how the "quality" of his "work" has "deteriorated" over the years.