It is not easy to add something, looking at the pictures should be enough, as the place is really that beautiful. On the top of Exarcheia, from the huge terrace the view in the morning hours over the goldened top floors of Zoodohou Pigis to the top of Lofos Strefi will leave wihtout breath. For those hating morning hours, like me, no worries, the sunset is not less unique.
You are near to the Platia Exarchion, to the restaurants in Benaki, to the metro. You can go easily to the top of the Lykabettus.
When you want just to relax at home a perfect kitchen with all what you can need to cook (trust the Italians) is there, and for the siesta the hifi system will be your companion.
I did not mention the host, but finally you won't need him at all probably, as all is already organised. If you will, he's very easy to reach, but that is normal, ξενοφιλια describes well the Greek hospitality. I think you should not book here if you have no sense for beauty, as this place deserves full appreciation.