i was reading this in a search i did. i learned on a plane that has 1 inch dihedral, and i built my trainer with just one inch dihedral, and it flys great. i dont know how a pt40 flys with like 5 inches of dihecral or whatever it is, but my eclipse can do really quick rolls, loops, immelmens, split ess'es, and even hammerheads. i would deffenetly sugest the flatter wing dihedral!