I've flown with many US trained PPLs most of who weren't as good as theyshould be to have a licence.
The problem isn't that the British think they're the best, its just that would be pilots go the the US for cheap licences. They go to schools which push them through the PPL too quickly and with too much hand holding. Then they come home to Great Britain where every thing in aviation is wierd to them, They probably haven't flown in months and virtually can't fly.
Some off my own students who have been to America told me the instructor they had pulled their flying to bits and the different ideas (joining downwind at 45 degrees) mesmerised them.
Airprox