My wife and I stayed at Theo's place. It was a hidden gem at Athens. It is nicely located where Omonia Square is just 5-7 min walking and Syntgma Square is 15 min by walk. The bus stop is literally at the door step (2 min walk). There are plenty of local stores near by, even there is a super store is just few steps away. I felt safe in his apartment which was located at the fifth floor. It had a small balcony which was very useful for morning and evening tea. You have also access to the roof top garden located above 7th floor. You have to climb 10-15 steps to reach there. There are plenty pf chairs and tables where you can just sit back and relax.
During our stay I noticed that in the night Omonia square had more homeless people. They never bothered us even we came back by walk around 11 pm.
Theo is a great host and great communicator. Theo was there at the apartment for check-in. I guess he also lives in the same building. So, he is just a call away. He provided us with all the guidance on how to reach his apartment from airport using public transport. When I mentioned that I need to work from there, he put a fast speed internet router for us. It helped me to continue with work from there. I also felt safe while staying there.