Nope, on my 1.42ghz mac mini even stuff like Aladdin isnt quite perfect (although its pretty close). Having said that though Ive not spend much time fine tuning euae config, so there's probably a little more juice that can be squeezed. From my experiences with it on othr systems, and the difference a bit of tuning can make Id hazzard a guess it could be maybe 10-20% either side of a stock a1200 without fastram (depending on the game)..
I'll try tonight, but i'm confident Aladdin would run just nicely on Mac mini, and that it even would on my Pegasos2. But that's assuming you use a fast output driver like overlay mode or cgx, and not the SDL version that crawls.
The performance of UAE on a G4 mini should rather be considered as something like at 68030@~40MHz or so.
On the other hand, it would be unsufficient for demanding applications (but most of them run directly in MorphOS anyway) or games like AlienBreed3D, Breathless, of course.