COURTYARD WINDOW! No motorcycles or cars to be heard. Haris' place was the quietest and by far the best among the three places I have stayed at in Thessaloniki. Great if you need rest - I was attending a conference. Still, keep in mind that the internal walls let everything go through so you will likely hear each other and the fridges, doors, and, unfortunately, the lift. That was the case in all 5 places I stayed in Macedonia, though. Haris' place has also good, modern windows.
Located right by the Agia Sofia, very close to the nice restaurants at Navarinou Square and close to Rotonda as well. For live music Friday night go to the cafes and restaurants around Rotonda (also music students playing rempetika together) or the Athonos Market. Step in for an evening service in one of the churches - for me the Orthodox chants are just amazing. I went everywhere by foot.
The studio is very clean and neatly arranged. I was very happy about the books about Thessaloniki and guides of the region Haris shares with guests.