This was my first time using Air BnB and I have to admit that I was a little nervous about it, but the room was exactly what we needed and made for a very reasonably priced stay in Vienna while not being far from any of the sites. There are also several traditional restaurants, a traveler specific bar, a grocery store, and a bakery all within a 2 minute walk. We were also left with instructions for where to go in case we had any medical emergencies (thankfully we avoided those) and very detailed procedures so there was no question about where to go and what to do. The only issue we ran into, albeit very small, was a spotty internet connection, but I contacted Dan and he helped us through it in a very prompt and professional manner despite the late hour. I highly recommend renting with Dan and Vienna Rooms for the Haidmanngasse location!
As a side note: I really enjoyed the key drop. No hassle with a check in office, just pick up the key and go. It was great!