Better than a hotel! I would stay again for a short trip to Berlin.
Supermax is a friendly host and tries his best to take care of the guests. Unfortunately, some circumstances outside of his control caused my stay to be cut short. I think the communication could be better overall, but he will answer any questions for you. That means, if something is unclear, just ask. The self check-in process was confusing, but it was at a convenient time and eventually made sense.