Mine has done around 130 electric flights with no structural issues. I did fit the rear bulkhead, tail support plate and a wooden ladder crutch. It has wing and tail adjusters but I bonded in the rear wing incidence tube just in front of the adjusters to support the fuz in this important area.

It is certainly the best flying model I have owned, far superior to the Angel's Shadow which it replaced. I am building a second one now. As far as the rolling issue, mine is best with conventional differential - more up than down but I have still to seal the bottom of the ailerons to eliminate the shriek on snapping.

I don't have any problems with getting the servos in and out as I made a long extended hex driver and use hex headed sheet metal screws to hold the servos in. As far as the geometry is concerned having the two horns operating in the one plane (geometric plane that is!) must be better than in two. If you don't believe me and you have access to CAD plot the input and output angles for a two plane linkage. As my model is electric I don't need ball raced horns so I use the supplied fibre ones in the surface and th largest Dubro heavy duty one on the servo (JR 8401). With the clevis in the outer hole on the servo arm and the second outer on the aileron horn I still dial in 120-130% travel for the snaps with much less for normal flying. This is no different to the setups I use in conventional servo mounted models. With these hole positions the pushrod gives some conventional differential right off and I add some more on my 10X

Malcolm - satisfied Impact owner