First, a clarification: I actually stayed with Anna on two separate occasions. The first time was for one month (mid-February to mid-March), and then the second time was for one weekend (end March). So this review covers both visits.
Anna is an extremely warm host. While I was there, she would quite often share her food with me, or invite me to try cakes and pies that she just happened to have made. She also invited me out with her friends, including for day trips in the surrounding area. Throughout my stay, it felt much more like I was staying with a friend than in some kind of "hotel".
At the same time though, Anna respected my privacy when I wanted to stay in, or had things I needed to do. I think she is very sensitive in this regard, and will give you as much (or as little) space as you need during your stay.
The flat is in Ano Poli, which is a beautiful part of the city - the most beautiful, if you ask me. I would say that the area is residential, so it's not the place to stay if you want to be surrounded by cafes and bars and nightlife. On the other hand, it only takes about 20 minutes to walk into the centre, and there are buses about every 20 minutes or so, if you do not fancy the walk. Also, the flat does have a good cafe just round the corner, as well as a few excellent restaurants (Igglis and Toixo, Toixo to name just two) within 10 minutes walk. It's just that this isn't the part of town that you go to if you want to party.
The flat itself is comfortable, and equipped with all the things you might need for a short or long stay. It has a balcony with lovely views of the Mediterranean, and on a clear day you can see Mount Olympus. The flat also comes with a dog, Frida, who is well-behaved and fond of people.
I really feel extraordinarily lucky that I stayed here during my stay in Thessaloniki. I would happily recommend this flat to my friends and family, and would stay there again in a heartbeat.