Helmuth was fun, friendly and helpful. I had trouble with my train ticket and he helped sort it out, also guided me in when the connecting train wasn't lining up. His place is a bit outside the main core but it's not a bad walk (maybe 20 minutes) and there are trams and buses close by, plus a cute little church, local restaurants and the Donau canal.
If I come to Vienna again, I will definitely stay with Helmuth and continue some great conversations.