We rented this appartment with 12 friends (mixed). This appartment never felt small at any moment, in fact it was very spacious. There were 6 bedrooms, so we never had to share a room with more than two people.
Furthermore, there were three bathrooms that were accessible through the hallway, and one bathroom that was ensuite (e.g. it was located in one of the bedrooms), which was very convenient with such a large group.
We did not made a lot of use of the large outdoor area, but I can see when it is nice weather, that one can enjoy it very much by having dinner outside or just a drink. There were enough chairs and tables outside to accomodate everyone.
Everything was nice and clean. However, the bathrooms are showing signs of age. Some of the showerheads had no wall-mount, so you had to hold it when taking a shower, a little annoying. Also, one of the heaters in the bathroom was leaking, so there was a puddle of water on the floor each time.
Other than that it was good! In order to get hot water, you have to push a button in the fuse box, after a few minutes, hot water is available. Even with such a large group, we never had a cold shower.
Dora is very friendly and responds very fast to messages.