I've been flyin' my UCANDO (90 size) with a Saito 100 (inverted) with a Cline regulator and APC 16 x 4 prop. Engine spool-up is a bit slower than the 15 x 6 but more thrust and slower speeds are my preference. I can't get the plane to Harrier, (upright - haven't tried inverted) even with up spolierons mixed with elevator (up ailerons with up elevator). CG is way aft - with a 6v 1650 mah battery in way aft fuse. But, the plane will hover all day and do slow close-in aerobatics either on the wing or the prop.

When assembling new, I epoxied tri stock at the wing/fuse former and gear area. I have about a 100 flights with no problems