Anything more you can share about Zurich? I know it ranked in the top three with Geneva in the last Mercer survey . . .
Disadvantages include having an older population, being small compared to New York, having less of a startup culture than SF, being very expensive, having many hurdles to get a residency permit for an American, and various innocuous cultural differences that simply take getting used to.
That said, I love it there and am heading back.
Good luck with your startup!