I'll start by saying I'm from and grew up in Thessaloniki, live abroad and was looking for a space in city center while I was visiting, so I knew the location is perfect. Everything is at your doorstep, you can walk to most places anyone on a city break would like to see, and the area itself is full of cool little cafes, bars and eateries!
Communication was hassle free, as was the check in process - even though our flight arrived very late at night.
There were two downsides to our stay:
1. The people in the apartment above are very, very noisy. As early as 7am we'd be woken up by furniture being dragged, or items dropped on the floor, and we'd often hear shouting - we concluded there's a toddler upstairs making most of the noise. This would happen throughout the day, but was pretty constant early in the morning and in late afternoon. There was never any noise during the night.
Now, this is not something the owner of this apartment could do anything about, nor are they responsible. Additionally, if you're a true visitor to the city you're probably out and about most of the time and wouldn't even know, however for someone like us who's in the apartment a lot and goes out mostly to meet with friends, it became very annoying and we were thankful that we were only there for a short 4 days. I did not report this to the owner because, as I mentioned above, it's beyond their control.
2. The electrics leave a lot to be desired. It's an old building, as all buildings in the area, and although the apartment had obviously been re-wired, it could probably have been done better. I reported an issue with a couple of power sockets to the owner after we had left (it was not important during our stay) and hopefully they address these issues for the next person.
On a separate, but relevant note, a different power socket fried our Chromecast when we plugged it in to watch some Netflix, which obviously isn't ideal as we were without it for the rest of our stay. Again, I didn't report this at the time as the damage was already done.
I should add that there's a notice up on the apartment that does say not to use too many appliances at any one time, however the only things on at the time were the kitchen and bedroom lights, the AC in the bedroom, and the TV in the bedroom, so obviously the electrics are a lot more sensitive than we thought.
Overall it was a great stay because location and cleanliness were important when we chose this apartment, and not only it delivered, but was also great value and the people were lovely to deal with!