We stayed in Georg's apartment for a few nights at Christmas time. This is super nice, clean and well equipped apartment with a lot of space. The heating system is working very well. The kitchen was well stocked and everything you need to live is within walking distance.
Location is great - about 15-20 minutes by foot to the Opera House.
We really enjoyed our stay, as Georg is a wonderful and accommodating host! He allowed us to drop off our luggage till the late afternoon and that was very convenient.
We really recommend the apartment to anyone who wants to have a nice stay in Vienna.