RE: GP Slow Poke 25 size
I pretty much agree with iowanspctr about the "Slowpoke". I built one per the plans (no ailerons) and it flew O.K. but not great. It needed weight in the nose. It was good for a slow "Sunday flier", but not much else. I don't think ailerons will do much unless you make some design changes. I would however recommend strengthening the wing tips. They're too light and will break if you stare at them.
Good luck!
DaveB