The ROM auditing is excruciatingly slow! Even ClrMamePro on my much slower PC can audit all of the ROMs in a fraction of the time that MAME OS X takes. I suspect there's some optimization that can be done here...

I have a MacBook Pro (Core 2 Duo 2.2GHz) and 394 romsets, and after ten minutes it's not even through auditing the Cs.