My return flight from Singapore to the US includes a 5-1/2-hour layover in Zurich. I've never been to Switzerland and would like to spend at least an hour or two outside of the airport exploring Zurich. It sounds like the train is pretty efficient to get from the airport to the town center. Is 5 and a half hours enough time to clear customs, get into town, explore for a bit, and get back in time for my departure back to the states? What time commitments should I factor into my planning (i.e. clearing customs, going through security again on my return to the airport, etc.). Any tips on what to see in Zurich on a compressed time schedule?
Thanks in advance for any tips and advice.