We had the bunk bed in a quite a large room on 5th Floor in the corner. We could hear the tram noise in the middle of the night but it was not too bad at all. The hotel is outside the city centre but the advantage is the price.
Likes: polite staff, very clean, design and colours (very funky), almost brand new, the breakfast, the shower, the electric sun blind, the shampoo and shower gel, the ease of getting to town and back (on the tram), they accommodate all your requests when you are making the booking, they reply to your emails very quickly.
The niggles: I had a small stain (blood or something above my bed), no kettle and no tea/coffee making facilities, no small towels to wash your face/ body with, the price of the sauna (15 CHF for the duration of your stay- regardless of the number of nights).
Tips:see my tip for choosing a bedroom. To get there, use tram number 4 Nord just outside the Zurich HB, at front of the Starbucks. Get off at Toni Areal. It takes 10 minutes on the tram and 1 minute walk from Toni Areal stop.