I've had all three of these planes. The Showtime is the best at KE. The Mayhem is the "toughest" and will do the very best flat spins. (amazing) But when all is said and done I always come bact to the UCD60. I love that plane. It is simply the most fun to fly. It does far better rolling circles than the Showtime but won't hold a candle in KE and Harrier.

Given your engine selection I like the UCD also because it is lighter than the Showtime by a pound. The Showtime also has the tendency to tip stall.

The Mayhem is a great plane. Because it has less tendency to fall apart than the other two and is a compromise, I think it is the better selection.

That being said...for most I'd suggest the Mayhem. But for me, (I don't mind fixing the rudder every 10-15 flights) I'd go with the UCD.

I'm sure this clears it up for you.

Thanks
Barry