blade002 - firstly, thanks for the kind words
The issue isn't with 68k/OS3.x's ability to handle the interface, but rather the HivelyTracker replayer. This is 16 channels of precision-stereo through AHI, so it's software mixed before being shoved through Paula, and each channel also has dual effects columns... So the replay routine currently needs at least 68060, and even my 060/60 struggles with HivelyTracker a little bit. Fair play, of course, since Hively was written specifically for OS4 and it's only thanks to Buzz^IRIS' sterling efforts (and my incessant nagging) that it was backported to 3.X anyway...so we have to live with the performance issues
There is one hope for a more usable 3.X replayer, and that's if Stingray^Scarab can find the time to write an optimised ASM replayer, which he thinks might allow Hively replay on 030. He's very busy, though, so it could be a while
Anyway, if an optimised replayer comes along, then it'll be worth Xeron's while porting to 68k 3.X...although since he's made the source available, I guess anyone could do it!