We really enjoyed our stay at Sonia's studio apartment. As other reviews have mentioned, there is a loud church nearby and a loud tram station also, however both of these quieten down by around 11pm.
The room itself was very clean, well presented and the bed was very cosy.
The facilities were excellent, with a well stocked albeit small kitchenette, includinging a fridgefreezer and dishwasher. Sonia provided coffee pods and tea bags as well.
Location wise, the studio is situated 10 minutes from the center of Zurich and is literally round the corner from the tram stop with regular number 10 or number 9 trams to reach the train station and city center respectively.
The area is a student area, visiting in September we felt very safe walking around the area at day and night.
The only minor issues for me were that the shower head was a little awkward, not really staying where it needed to, and the window next to the door doesn't have a shutter on it and there is a light directly outside it which shines through the window at night. However, neither of these issues are reason not to book, the studio is perfect for a short break in Zurich, especially if you have travel passes for the trams.