(Out of curiousity, what's in your AROS box? 3GHz suggests P4 to me, and if that's the case, it ain't AROS that's running like crap. Netburst sprints like a cheetah, but it corners like a yacht.)
Anyway, while the eMac is no great shakes (I'd check your local school and/or recycle center for a later Power Mac G4, you can get them for peanuts,) I have to say I've been pleasantly impressed by MorphOS - while it still fundamentally feels like an early-'90s OS (though in my mind that's no bad thing,) it's got a nice amount of polish and hangs together nicely.