David was very helpful and really nice. He helped us with getting to his place and then thoroughly showed us his home along with the rules. We had a big, clean bed with towels ready along with tourist guides on the table. We spent only a night at David's place and then we had to continue on our journey, so I cannot say much more. But I am sure that this is a good starting point for discovering Vienna since it took us only about a 10 minute subway ride to the main square.