I've spend two nights at Thomas and Bettina's apartments with my friends. We really enjoyed our stay and I was a little sad that our vacation was so short. Both appartments are really similar, whilst one has a slightly bigger couch and chill out area, and the other one has a slightly bigger kitchenette and bathroom. Both spaces are really comfortable and equipped for all needs, and the rooms are bright and you can overlook a nice garden area with trees and chirping birds.
While we didn't meet Thomas and Bettina personally, our communication via Chat was always timely, friendly and very helpful. The self check in was easy, so was accessing the provided bikes (that took us to a very nice lake recommended by the landlords). There are several grocery options within short walking distances and the city center is about 20/30 minutes away by public transport.
I can wholeheartedly recommend this stay and would stay here again :-)