Günter is a great host. He responded promptly to any questions we had during our three weeks in his apartment. The apartment is very comfortable and quiet. The location was perfect for us, in that it was right around the corner from our daughter's apartment, but it does take an U-bahn ride to get into the center of the city. That said, the trams and U-bahn are frequent and reliable, and you can buy day- and week-passes for unlimited city transportation. Everything you would need is within a 2-minute walk on Mariahilfe Straße -- grocery, pharmacy, office supply, etc.
The apartment really holds together well. The appliances are new and work well. The furniture matches, and there's no idiosyncratic art on the walls, which makes the place restful to be in. It doesn't feel like someone else's apartment, or a place for leftovers; it's intentionally designed as a comfortable airbnb apartment. We would stay here again!