Yiannis' place is very nice and stylish. I visit Thessaloniki a lot for my work and I think that the apartment was one of the most modern, clean, and well designed places I've stayed.
Unfortunately I didn't think the check in was very good. I was visiting from London and I told the host I expected to arrive at around 4pm.
When I arrived at 2pm, he was not able to meet me until 4.30 so I had to sit on the street for hours waiting with my heavy luggage. I understand that I had told him 4.30, but he should have some flexibility for international guests and their travel schedules. I was only in Thessaloniki for 3 nights, and unfortunately spent my entire Friday afternoon waiting for him. By 4.30 it was already dark.
The area is a little sketchy at night but at least it is close to everything .