As a company of 4, we stayed at Stelios' place for 3 days in our trip to Thessaloniki.
We had a fantastic time.
The apartment was gorgeous, with a high ceiling, vintage style (but not old) and with a lovely balcony.
It was extra clean and it literally made you feel at home.
Of course the location is perfect, in the heart of the city, 2m walk from very nice coffee shops, restaurants, brunch places and bars.
Also Stelios' suggestions were spot on! He was very quick on his replies and although we did not meet him in person, we had an excellent communication.
He also was very flexible on the check-in and check-out times.
The thermal insulation was perfect and you could have as much heating as you'd like (it was winter time), as well as hot water.
One of us was sleeping on the sofa bed, and had no problem at all, it was very comfortable.
The street has the rare parking spot which is paid (except Sat noon to Sunday midnight i think) so if you're coming with a car you'll need to use the nearby private paid parking lots.
We couldn't really find anything negative, so it is highly recommend and of course we would stay there again.
Thank you Stelios for everything.