Whats everything that is good and bad about gutbuster?

Well a kid at the competition at Magic Camp performed it and one thing that is bad is that the method is obvious.

If done right, its awesome. My friend and I did it at school the other day and this kid in my broadcasting class dlipped out and almost cried. The thing I worry about most is acting. It needs to be pretty good quality. I mean what happens when you yank your arm back out. Do you say, "sorry man. At least you're fine."
what I do is is started taking about how I can do wierd things with my body like letting things pass through. (Perhaps I just did the string through the stomach thing, or chain through the neck) and then I say watch, and my assistant comes and slams his arm through my body. I dont know where Im goin with this. Its a nice trick, but most people can figure it out.