I've built both with flaps on the smaller one. Either slows down so well flaps are more of a conversational item than a useful one, IMHO not worth the added bother. I much prefer the tail dragger versions but that is purely an individual choice. One thing you must watch out for is wing warp. It is very easy when covering the wing to get a warp in it. Do not use a fabric covering, you need the added stiffness that the mylar covering give you when they are shrunk tight. Propery designed wing struts do help in keeping the wings properly aligned; if you use them, build them as working struts, not just ornamental. Just check carefully for warps befor first flight and use a heat gun to remove any if they exist.