communication with the host was very fast and easy. Check-in was well organized (host even organized a mini-van to pick us up (a group of 7) at the airport for a total of 80€ one-way).
The hosts son was waiting for us at the appartment, welcomed us and showed us the apartment.
The apartment is large enough. Generally, traffic is very loud and even with closed windows it's noisy during the night. Only one of the three-persons bedrooms has good shutters and is quiet during the night.
The boiler for the bathroom has to be turned on 30minutes before you want to have a shower and then you have enough water for 4 persons to shower. The host told us to turn off the boiler once the water is hot and then when we have a shower and also when we leave the apartment due to safety issues.
After check-in, the hosts son gave us recommendations about what to see and what tours to do. The information, he gave to us wasn't always correct (especially for student-discounts) and the recommended restaurant was more for tourists than it sounded when he told us about it.
But he gave us a nice introduction into the main attractions of athens, the greek food and transportation around downtown.
All in all, good price-performance ratio for a big group (just make sure to bring earplugs)