Travelled to Zurich to work on my third city guide (app) and decided to stay at the B2 (B Square). What a very pleasant surprise. Compared to other hotels the rates are fairly reasonable for Zurich and for Switzerland. I had a regular room but it was so well appointed. From the moment I arrived until the moment I left the staff was warm and welcoming and always helpful. Included in the room is breakfast (all local products such as cheeses, meats, etc) with muesli, croissants, juices, etc - all very good quality. A minibar is stocked with coke/diet, flat/sparkling and beer or OJ replenished daily and FREE. Wifi was also free (we love that at onestop). The spa/thermal baths are not owned by the hotel so you have to pay to use them but it's CHF25 for 24 hours (actual 24hrs, not per day). You have a private entrance from the hotel and can use the bracelet they give you to access it and even charge items such as food, drinks. As some people have mentioned before, weekends are mobbed and you will enjoy it much more during the week.
The hotel is walking distance from trams, SilhCity with movie theatres, shopping, etc and also around 15-20 min walking distance to main train station or Banhoffstrasse. The cab I took from the train station when I arrived was around CHF25-30.
My room was 121 and had a great view, was extremely quiet and everything worked perfectly with a comfy bed. The place was spotless. My only criticism is that the hotel doesn't have a gym.
I look forward to coming back some day.