I had a great time in Theodoros' place - it's in a really central location, it's nice and clean and has a nice balcony. Theodoros was also very friendly - meeting me on my arrival, providing bottled water, lots of maps, etc. for Thessaloniki, and he was always very responsive! The only slight downside was that it was a bit noisy at night, but that is expected due to the central location in a busy city!