My friend and I stayed at Christos and Christiana's apartment for a week, and we felt right at home the moment we walked in. The apartment is big, and even had a whole extra room we didn't use. The beds in particular were super comfy!
The location is great if you want to stay someplace a little outside of the bustling center, but not too far (about 15-30 minutes walk, depending where you want to go. Plus there are bus stops everywhere!). We felt like locals, buying coffee at cute little shops about 2 minutes away, and then walking down 10 minutes to the promenade to get some fresh sea air.
Finally, Christos and Christiana were very responsive and helpful with instructions and responded quickly to our questions. They were very flexible and kind, even leaving us a bottle of wine and fruits to enjoy. I highly recommend this apartment to anyone who wants a relaxing Thessaloniki vacation (or workation in our case, haha!).