Lovely studio, super comfortable bed and pillows. Easy to go in with the keys in a self check-in box. Bathroom is very nice and clean too, shower a bit small but manageable. Really enjoyed having a mini kitchen and the use of the washing machine as well as the patio/balcony. You can just see the sea from the balcony too. Easy walk from the train station to there and near a bus stop for the airport as well. There are also restaurants and a supermarket nearby that are all nice.
My only very minor issue is that it was extraordinarily hot in Thessaloniki (more than 35C) when I was there; so with the A/C not being near the bed area, it took quite a long time for it to cool off inside the flat, even with it on the lowest temp and highest fan setting. So, it was a little warm to sleep the first night. However, after leaving the AC on all day the next day, it was much more comfortable. If you go in any season not summer, this would not be an issue at all.