Zurich is just a personal preference because I studied and lived a long time in Switzerland. If you drew a cultural and demographic vector from Berlin through Munich to Zurich, you'd have a pretty good picture of what Zurich is like. If that sounds like a mixed bag, that's because it is. ;-) Even richer, even better working, but also even stuffier. I love it there but that's because many of my friends are there.

What is true, though, is that Switzerland has a better business culture and regulatory/tax environment. People work quite hard, they are very rational and pragmatic in business matters, and the universities there are, unlike the German ones, truly world class. I'd also wager, although I've not (yet?) tried myself, that it will be easier to raise capital from Swiss investors than from Munich-based ones (and Berlin, as someone already mentioned, doesn't really have serious capital floating around).

It's all a wash though, I'm sure that these generalities have marginal impact on whatever you or I do or decide. At the end of the day, sitting in Munich, you're a productive 4h train ride away from Zurich and a 6h train ride from Berlin.