For what its worth: I have PT40s with the larger dihedral angle and the plane is actually rather difficult to control when it gets windy because of this. OTher pilots when they first see the plane on the ground think that the builder made a "mistake" with the huge angle of the wings! I built a LT25 with only 1" dihedral and the plane will still self level if you leave the sticks alone but the plane flys very well in fairly windy conditions and will fly the circuit inverted until you run out of fuel if you want to.