This apartment is an excellent place for 2 - very near central Vienna as described. We could walk into the centre easily but the trams (which are a wonderfully convenient way of getting around) are just around the corner. Several nice places to eat nearby in a good area. Also grocery shops.
The apartment is clean and cosy, spacious and very well equipped. There is a lovely entrance hall and stairway to the building. The Wifi worked well and the heating is very effective (and we were there in November when it was pretty cold). Shower and washing machine also worked well.
I see other people commented about outside noise - the only thing we heard was the 6.00am emptying of the bottle bank a couple of times!
Georg was very obliging about our late flight arrival - by the way, if you arrive late I suggest you do not get a taxi as it was 50 euros (and not much quicker than the train as we found out when we set off for home)!!
Definitely a good base for exploring Vienna