Hey, I have that bird too. You are right, the roll rate with aileron alone is painfully slow, and it does get small FAST in the sky. I powered mine with an os 50sx swinging a 12/5.
I get unlimited vertical and very nice down line speed. I did learn the hard way that this plane is very sensitive to the cg setting so be careful if you decide to "nudge" the cg back a little.