I have stayed at Orfeas place for several weeks and I have also extended my stay several times. It is a great place - very chilled and relaxed and with all amenities. The area is very nice as well - it is right next to a small park and it is in a quiet area but still close (about 15 min walk) to the center.
Orfeas and Maria-Louisa are very kind and extremely helpful and both of them make you feel very welcomed and at home.
I highly recommend Orfeas place and if I return to Athens then I will definately book this room again.