The stock motor is fine for 3d, Lots of power. If you look at the videos on stmodels.com the plane in those videos is using the stock motor. As for strength, it is foam. So it won't survive a crash to well. I have broken mine a few times but was able to repair fairly quickly. Most repairs were due to fatigue of lots of landings (gear bends or rips out from fuse)

Khameleon