Frank's place is a good option while in Zurich, considering how expensive the city is. Location is great, close to the tram and to several bus lines. 15 minutes to the old town. There are supermarkets nearby and restaurants (although I have not tried any). On the cons side, the fact that the couple's room doesn't have a door is worse than what I guessed before. It is not only a problem of lack of privacy, if your partner goes to the kitchen during the night and turn the lights on, you will be disturbed. Summing up, considering you are in Zurich, it is ok, I would book there again.