I loved the tour! Cohen was very friendly, he took my wishes into account and explained a lot about the beautiful town of St. Gallen. The main focus of the tour was the history of the town, but Cohen always combined it with architecture, art and the present (so e. g. at the train station, he explained about its history and what it was inspired from, how they built it, what the new construction there is etc.). I felt that he feels really passionate about the town and he tried hard that I could understand everything he explained. He could answer many of my many questions and I learned a lot of new things about St. Gallen although I have been there already.
As I read the comments that the guide didn't show up I contacted Cohen directly and he answered to my massage and confirmed the tour personally. We agreed on another meeting point as I arrived at the train station and he was there before me. So I guess that if you contact him via e-mail and he responds there won't be a problem :)
I felt welcomed and learned very much, so recommend this tour a lot! :)