I'll sub out parts of jobs, but not entire jobs. If subbing part of the job means that I get the entire thing, then that's what I have to do. There are a few clients where I will be the GC because they are never around and I can count on them to pay.
In the long run though I think it's better to not get involved. Right now I am waiting for an invoice from one guy so I can send out a bill that I think will be somewhere around 6K. If he's higher than I am guessing then I am SOL, if he's lower then I guess I pocket a bit more money. On another job I am going to be having some legal issues with a sub because he took certain liberties that he thought he could get away with.