Me and my partner stayed at Panos's place 3 nights in January.
Panos as a host is wonderful and happy to help with anything and he replies within few minutes! The apartment is as described, the location is great - very close to the city center. There is a bakery across the street and Victoria metro station within 5min walk.
The neighbourhood seemed less safe than we expected, but overall it was fine. It was cold in the apartment for us but it was also unusually cold for Athens (To make it clear you can use a A/C or a heater to make you comfortable, but for us it wasn't enough. But again it depends on a personal preference.)
Feel free to ask Panos any additional questions about your stay, he will be happy to answer. Over all I can say that in spring or summer it can be wonderful place to stay.