Paul,
I flew mine here in the Denver area with two Magnum .42's with 3 bladed APC's and it flew great and very scale-like at 1/2 to 3/4 throttle. The APC's would load the motor just right (~10,000rpm) for a nice sound, too.

I had a radio hit and caused it to flat spin in but I hope to build one again soon. Loved that bird!