First things first: we visited Vienna in the middle of a heat wave (35+ C) and the air conditioning worked perfectly - the room was perfectly cool and comfortable despite the sauna outside. Priceless!
The room was big and the beds comfortable. Reminiscent of Embassy Suites in the US, with living room area and bed room area.
As a sidenote the rooms does not have the advertised micro,and the fridge was actually a fully stacked minibar (there is room to put in your own stuff, but it's a bit limited).
The staff is friendly and service-minded. Breakfast buffet is somewhat limited, but fully OK.
Good, quiet and very central location: 300 m to Schwedenplatz where you can get on the underground, trams, buses and boats to anywhere. Another 400 meters gets you to the Stephansdome.
The airport bus (a 20 minute comfortable ride) also stops near Schwedenplatz - a good alternative to car and train to get from the airport.
Highly recommended