Maidened my four star 40 yesterday.
I sheeted the wing from the LE to the main spar, this added alot of additional strength and IMO improved the aethetics of the wing LE.
I have a Saito 56 in mine with an APC 12x6 prop pulls really nicely and I love the sound of the engine.
If I was to build another 4* I would do the wing mod again.