Yannis was a great host who gaves us loads on information about Thessaloniki. He is very passionate about the city and its foods, so if you are interested in eating at good places, he knows where.
Apartment was good, quite a good location, we enjoyed our stay! Yannis even organized a transport to the airport early in the morning for us and his friend who picked us up was a super nice guy to talk to as well!
Just one note about the parking, it is a small street where the apartment is, so you will be down on your luck to find a spot. We had a car rented up to one day after our check-in and we luckily got a spot right in front of the entrance, however it was actually not allowed for parking and right next to the entrance/exit of a private parking garage, so it wasn't optimal but worked. Just a word of caution for everyone having a car during their stay, you won't really need it and it may at times be difficult to find a good spot to park.