The problem for Americans (that I have talked to here) is that allegedly your IRS is absolutely ruthless at taxing you even if you decide to settle down here. I'm sure good accountants help, but some people say they are having even problems opening bank accounts. Banks are afraid or the IRS too somehow.

Otherwise it shouldn't be a big problem, I guess you do have to bring something to the table compared to the same local guy, but life's more relaxed here. If you like that, it's a good idea. If you are crazy ambitious money and career wise, nothing beats America.