We were very comfortable in the apartments. They are clean, cozy, and provide coffee, shampoo, conditioner, lotion. BUT upon arriving in Germany Numa Kater emailed that the two bedroom unit we reserved was no longer available and they had two separate one bedroom units for us instead. We were traveling with children so this meant my husband and I had to stay in different units and we had to sleep on the pull out sofas and share beds, which wouldn't have been the case with the two bedroom we originally booked.
That being said, the apartments were clean and very comfortable. They provide a lot of space for the money and we felt safe. The hallway leading to the apartments is dirty and the front door (not a security door) had a broken glass window. It is definitely more of a late-night area, but we enjoyed the location, the food vendors and easy access to the Sbahn station.