i have actual proof of the advantage of a balsa skinned foam wing vs a built up balsa wing. over the weekend i crashed a .45 size speed plane full speed nose 1st into the ground. the plane left a 8" deep hole but the plane essentially survived. the sickening crack i heard was only the wing momentum tearing a few pieces of the plane off between the wing and the fire wall. the wing survived completely intact. what i thought was going to be balsa shreds ended up being a few rebuilding hours to get the plane flyable again. no way the wing survives if it's all balsa.
david