We spent 6 nights in the flat during the Christmas holidays. The location is so convenient, everything is within walking distance, it is perfect if you want to be downtown.
The flat is modern, spacious, clean, with all necessary facilities.
One drawback was that there was no heating in the bathroom, which was perfect, but quite cold. (The weather was very cold during our stay in Thessaloniki).
Oh and there is no lift for the specific flat, so it was a bit tiring to carry the baby's stroller up and down the stairs.
Other than that we enjoyed our stay and would recommend the flat as it is a pleasant place right in the heart of the city!