Which version are you building?
I built the 4 ch and i can tell you that the wing spar is not strong enough, you have to add carbon fiber spars. In my case i added a couple of wing struts. Same happens with the tube of the fuselage, you need to reinforce in te union with the main body. Mine in the first landing at the moment of fairing bent when touched the ground. But anyway its a great flyer.