We have stayed in many Airbnb places in Salonika and, overall, this is by far the most enjoyable yet. It is in our favorite part of town, has a wonderful terrace with fantastic views, a well equipped kitchen, an excellent bed, a pleasant indoor space, first rate wifi, easy check-in, and a very responsive host.
There are a few things to consider, however. It is fairly high up in the old town which means a lot of serious up-hill walking to get anywhere, and while taxis can get you fairly close, the narrow, one-way streets make it hard to get to the door. Then, once inside, you have to climb a steep, narrow, and fairly long staircase that isn't all that easy to negotiate, especially with large or heavy bags. But if that isn't a problem, the we can't recommend Ilias's place strongly enough.