Our experience with Andreas was very positive. He was very prompt for our scheduled meeting time and in responding to messages. His instructions for the apartment were very detailed and thorough.
As for the apartment, it is small but clean and very functional. Thessaloniki is a city that is best explored by walking so much time should not be spent in an apartment anyways. The price is good for the location and I would recommend both Andreas and the apartment for anyone looking to stay in Thessaloniki.