There are three sides to Switzerland as you may know: French, German and Italian. The sides that I mainly have experience with are French and a bit of the German side. Both sides take themselves very seriously, but the French Swiss are more reserved than the German Swiss. And you are right, sometimes when they greet you even though they know you well, it's done with a very strict face. The Swiss Germans seem to be a bit more outgoing and will go out for a drink and in general are more friendly. They do appear to be more honest in business than in the UK in that they will generally let you know what is going on as opposed to keeping cards too close to their chest and they don't tend to lead you up the garden path with false hopes. In general they are not great talkers though will say what is necessary. I'm not sure if you speak German but being at your customer's base in Zurich, speaking German would help although English is the second language of the German side of Switzerland. This is not the case in the French side where German is the second language and English does not appear to be as widely spoken as in the German side. The office that I worked with in the French side was extremely quiet. You could hear a pin drop, which I found quite good when focussing on something in depth. That's my experience and I hope it helps. Others, no doubt, on the forum will have different experiences.