I bought one right after the original post (thanks Jokersmoker). I am a terrible pilot. After about 8 minutes of use, during my second or third cartwheel landing, the rear wing kind of twisted around and ripped the foam material a little bit. I went home and fixed it with glue and duct tape. I went back out and after a few more crash landings found that the rear rudder didn't work properly anymore - it wouldn't return to center after a turn, making the plane nearly impossible to maneuver.
So 7 days after buying the first plane, I saw that the price had come down to $39.99 and I bought another. It took about 10 minutes of flying (including a few more cartwheel landings) before the same sticky rudder problem started happening. I can't say if the sticky rudder problem is due to my repeated crash landing or due to some type of electrical problem in their production process, but I have had it on two planes.
It is so light, that you really have to fly it in zero wind or it blows around out of control. That all said, I love the plane. It takes about 1 minute to set up after you charge the battery. Only buy it for your son if you live somewhere where there is no wind and you have a big area to fly in, or if your son is a pro pilot.