my German boyfriend chose this place because it looked like an atypical guesthouse in a city of massive tourist hotels, and he was right. It was a bit hard to find, located behind a rather anonymous front of modern buildings (and on a street where a few ladies of the night prowled when we drove in) but it was definitely worth it.
The house itself is lovely, and our room had the highest ceilings I've ever seen. The cleanliness was a biit iffy (some dust bunnies behind a cupboard I pulled out to plug in my phone charger, and some long-unusued toiletries in the bathroom) but the overall feeling was extremely pleasant and cozy.
Breakfast is served in a bright room at the top of the hotel was a proper German hotel breakfast, very carefully laid out by the proprietors who definitely seem to have a certain amount of pride in their operation. It also showed that the clientele of the place is quite mixed. There were several families with children of all ages (from about 5 to teenaged), a few couples, and some older business-type fellows. All were German though.
The location's quite close to the usual tourist attractions so it's easy to go by foot if you're interested, but there's also plenty of metro options in the area. After a whole day of traffic noises and walking on the cold streets, this hotel was a great place to return to for some quiet and coziness.
We had a car which we parked in their underground garage for 5 Euros a day, and they were agreeably flexible about letting us stay a few hours past our checkout for no extra charge.
Overall, in spite of the few dust bunnies and the initially spooky impression when driving in at night, I would recommend this place for the small-town feeling of the place, the lovely building, the friendly and helpful staff, and the pleasant breakfast.