I've been based in Switzerland the last ten years. First for studies, now for work. In terms of schools: Bern is good for someone who needs a low-pressure, slow-going atmosphere to start. For someone already somewhat established studying there can be really frustrating. If you feel ready to hit the big stage then Zurich is the place to be. They get a lot of big names and have tons of money to thrown around. But, you have to be good, because unlike Bern they won't coddle students much and they just expect you to do your work consistently and deliver. I started in Bern and did some opera stuff later in Zurich. Both were helpful in their own way. There are other schools of course - Geneva, Lausanne, etc - all worth looking in to. In the end, it depends on the teacher you choose.
Switzerland is really small, everyone knows everyone and they have lots of money. Artists are supported and paid reasonably well. People here are quite musically educated and they expect a lot of their musicians. It can be high pressure. Swiss audiences don't tend to give a lot of energy and love either (as opposed to Germans or Anglo-Saxons) - I would say they offer more a distanced, dignified appreciation. They love someone who can tastefully let their hair down. But not too much

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If you can get established here do it. They don't work singers like dogs like in Germany and things are more relaxed. That said, I have heard some singers complain it is boring here and that it is hard to get integrated. I never had a problem with the boredom (but I have also hopped over the border for a gig or two). Integration can indeed be difficult. I think you really have to love it here, else it won't work.