This is a lovely flat in a convenient location. The hosts were good at communicating by email, but let me down on one occasion when trying to communicate about an urgent matter by phone (mixture of my German/her English was fine, but the call dropped - I called back a couple of times but couldn't get through, whereas she didn't try to call back).
The flat has one major disadvantage which is worth potential future visitors considering. In order to get in the front door you have to dial a phone number, navigate some menus, and enter a code, before the door unlocks - not just the first time you arrive, but every time you enter the flat. You then have to enter two further sets of six digit codes before getting to your actual room, which is tedious but at least you're inside. If your phone can't get reception, runs out of battery, or there's a signal weakness, then you can't get into the building at all. This happened to me in the snow and it was challenging to resolve. Ignoring this inconvenience/risk, the flat is otherwise very nice.