Burge, There's Nothing Like the Real Thing © :laugh
Anyway, I too think MAME has went a bit TOO far with spec needs. MAME is mainly so unoptimized to cater for cross development. It's got to be easily portable and that fucks it up.
I run Raine and NeoGeo games perfectly on my P133 (specially those neogeo beasts!), while MAME dies with them. Besides, it manages memory in a worse way than those two otherexamples. Single-system or more focused emulators always perform better, mainly because they don't use to be portable, they are more platform-specific.