If you are looking for a nice place in a very well connected part of Zurich I can only recommend to stay at Mario’s place.
He sincerely cares about his guests, reaches out regularly and ensure everyone is comfortable and nothing is missing for a great vacation/stay.
For longer stays, though it needs to be clear that this apartment neither has WiFi, nor a TV, which is fine, but definitely something to adjust to.
Anyhow, overall the apartment, though small, ist comfortable, clean, well located, and with a very kind host...definitely to recommend