Mark is a wonderful host! Really friendly, answer anything you might want to know about, and make sure you have a nice time there. The appartement is really nice, comfy furnitures, everything clean and nice. The balcony is my favorite there, I spent hours there every night. It gives you lots of sun, and you can also sit in the shadow.
There is a smaller balcony on the other side, so you can always find sun or shadow, what ever you prefer.
Mark brought a welcoming present, nice bottle of wine, and greek cake.
He lives next door, and is there to answer questions or fix things if that is needed.
One thing to be aware of is that it takes 20-30 mins to walk from Monastiraki.
There is an area there that is not too nice at night, but if you avoid that one little spot in the street, the rest is quiet and really nice.
I walked home late at night most nights, and felt perfectly safe.
I have already recomended this place to friends.