Bill,
I think your numbers are a little aggressive. You can do pretty good 3D flying
on 100 watts/pound. 50 watts/pound works for sport flying. I have a cub that
flies scale like, including loops and rolls on about 55 watts per pound.
My Gt17 flies fine at 19ounces with around 90-100 watts full throttle for loops,
and 1/2-3/4 throttle for climb and cruise. My rule of thumb is about 75 watts/pound for
small electric gyrocopters.
mickey