Last time I played MAME on my A4000T was with the PPC version. AGA is slow compared to my CybervisionPPC card. 060 version made it worse. The GUI is awesome plus additional features to adjust audio...
Unfortunately you can run on PPC the 1MHz games, like Pac-Man, Pengo, Robotron 2084, Defender, Stargate, Blaster (actually Williams you can get away since graphics use bitmap only while others emulate screens like the C64). Vector games like Asteroids, Tempest, Omega Race, Zektor, Star Trek you will have to adjust the video settings to make them work real-time.
Ya know, MAME could work a hell-of-a-lot-better on OS4 /\/\/\ Coders-->(hint) (hint) :-D
Now that I'm inching to play again, I may try the WES version and see what happens.