Hey WhirlwindII,
I came to the US with a UK PPL I got in 2005 and quickly realised that I knew absolutely nothing compared to someone who had done their training in the US. I had also done the JAA ATPL exams and wondered why I had spent 6 months of 10 hours study a day when I would have been better off being thought to be a helicopter pilot.
I've trained people from all over the world and I've always found that when a European ppl comes to the US to hour build, or get a CPL, their level of knowledge, and in most cases flying ability, is way below that of an FAA ppl - and I can say this without any bias because I was once that person! I thought myself, when I came over, that JAA was way more advanced, and quickly realised that us, as Europeans, are just a more arrogant people!
I believe that on the FAA side you learn a lot more about the machine you fly. I did all my commercial and IR flying in the US so cant comment on any comparison there.
Just another point of view from someone who trained in both places and has both licenses!