Overall, the experience was very good. The apartment exceeded our expectations. We only have two negatives.
First, our arrival. On the day of the check-in, we made a special request for earlier check-in. They said they could manage it. But it actually took 1 hour on the curb in front of the appartment and 5 phone calls before we were able to enter. Don't make promises you can't keep.
Second, the garden chairs. There are some plastic chairs in the garden. This in itself is no problem, however one of the chairs broke, while one of us was sitting in it. Despite weighing a normal 80kg and sitting normally. We don't know whether the chair was already damaged or just cheap, but it definitely wasn't fun.
All in all we had a good time, the appartment is very comfortable, easily accesible by metro and has a supermarket within walking distance.