We arrived at noon and they were very nice to let us check in at 13 even though the official checkin time was only from 15 onwards.
However the flat was extremely warm as the air conditioning was off. It took it a day or so to really take off. I just don't recommend this place in the heat of summer as the place is kind of an attic. Right under the roof makes it very damp and warm. The place is rather clean and spacious for 8 people.
The location is great however and the hosts are nice people always available.