I have a Giles ARF with a YS140 and another one with a Brison 2.4 gas engine. The planes weigh 14 and 17 lbs gross weight. I will let others do the math, but both planes land the same and other than pulling power, flies the same. The glow flies straighter because it was assembled straighter. Other than that, I can not tell any difference in performance.

I will agree that if you are doing 3D maneuvers, an extreemly light wing loading is desirable. What I don't understand is the wing loading difference in normal fight if your power to weight ratio is high enough to handle the extra weight.

Please help me understand the technicals!
Thanks