This is a wonderful flat for a short, or long stay in Athens. We stayed here for 12 days and were thrilled by all the small details that made our stay so great. The flat feels big (two bathrooms), and has ample space for all your stuff. Long benches, and plenty of hangers and space for your clothes. This place was created for the traveler in mind. Fleamarkets every day (extended on weekends), pedestrian streets filled with exiting shops right on your doorsteps. It's nice to live so close to shopping as you can always run up to the apartment with your heavy loads and keep on sightseeing afterward.
Be sure to take the extended 5-day ticket to the outdoor sights, as it is much cheaper than the individual tickets, and you are literally minutes walking from each and every one of them.
The kitchen is fully furnished and a great place to make your own food or heat up take-away.
Note that the Monastiraki area is known for its rooftop restaurants and nightclubs. Normally that would include a sound challenge at nighttimes, but Nikos has put in the most soundproofed windows we have seen, and also placed the bedroom in the back of the apartment. We are sound-sensitive people, and we slept like logs! :-D
We can totally recommend this apartment.