Even though I didn't spend much time around Jannis, I could tell he was a very nice guy, extremely helpful and hospitable. He quickly responded to all my questions and needs and made me feel at home. His place was spacious and clean and in a quiet neighbourhood, not too far from the centre: easily accessible by bus or even on foot (30-40 min walk). The only problem I had had to do with the insanely hot weather the first day I was there (end of July). The fan in the room provided little comfort during the night. My second night was much better because the weather was a bit cooler that day. In general, I would recommend visiting Thessaloniki in any season other than the summer if you can arrange it that way. It was simply too hot and humid outside (at least on my first day). In conclusion, aside from a problem associated with -what I would call- the extreme weather conditions, my stay with Jannis was very pleasant indeed.