My husband and I spent 6 nights in this apartment and we loved it. It was beautiful, very clean, and well equipped. The neighborhood itself was also great--a few grocery stores nearby, an outdoor market, and many restaurants and bakeries all within walking distance. There is also a great pool nearby and we took advantage of it, as it was very hot during our visit. The U-bahn station is just a block away, and it was very quick and easy to get to the center.
We didn't meet Helene, but her husband Rainer welcomed us and he also came to see us off. He was very nice, gave us helpful recommendations, and also left us a bottle of wine, bread, and a few other essentials.
All in all, we had a great time, and we highly recommend this place!