We were a group of 8 staying in the apartment for 3 nights. Firstly, the location is great. It's close to the metro so you can get around quite quickly, but the city centre and many attractions are also well within walking distance. Claus was also a great host and communication was easy. We also had a late flight, and he was very flexible with the checkout time, which made our life much easier.
The apartment is in an old house so be prepared for old house quirks, such as creaky floorboards, lacklustre soundproofing, one WC door that you can't close properly, et cetera. But if such things don't bother you, then it's a good place to stay!