The living space (walls and floor) is concrete so it is almost like staying in a cave. Additionally, if you are over 6 (six) feet tall; then you may have issues with the bedroom (since the height of the ceiling is about 6 feet). Other than those concerns, Grey Matter provides excellent value in regards to location. The rate is extremely reasonable (for a place that is in walking distance from the Acropolis). Additionally, this place had a washer/dryer combo (with laundry detergent) that the guest can use. This place does also offer an area to leave your luggage (if you arrive before check-in at 2PM). The host was also quick to answer all of my inquiries. Overall, I do recommend Grey Matter as long as you are not expecting luxury.