I always scan for crossing traffic landing at KSFO. Being on final at 200' and having an aircraft cross does make you a bit tense.
Having a European background, flying into the US certainly gives the impression of smaller margins: sudden change of runway late in the approach, a generally stressed atmosphere, sometimes sloppy phraseology. It's not that the individual controller is not professional, it has more to do with the overall culture and too high a workload, me thinks. Also, often things seem to be organized in pecular ways as alluded to above. London Heathrow also moves huge amounts of traffic, but you seldom get the tense feeling of chaos and stress from ATC there.