I stayed for 2 nights at Erhard's place for a quick weekend trip. He was welcoming and maintained a very clean place. The man himself is friendly, but will also give you space while being there if needed. Despite arriving at a late hour, he was there to open the door. However, as many have noted, be prepared to struggle against gravity going up 6 flights of stairs as the apartment is on the top floor. The location is good, a short stroll to a U-Bahn station and close enough to walk to the city center should you wish to. I would highly recommend Erhard to those looking for a clean, convenient place to stay and are prepared for a good workout climbing the stairs.