Albert is a great host, and his place is ideal for exploring Vienna. It is around the corner from Schwedenplatz U-Bahn station, although you won't need to get the train much because everything in the inner city is easily walkable (about 10min to Stephansplatz, 25min to the Museums Quarter). There are lots of restaurants and shops close by.
The apartment is very comfortable and spacious for a studio, with lots of storage for your belongings; the kitchen is small but well-equipped, and there is a washing machine and dryer in the apartment itself. I loved the view from the window over the Danube Canal. It is on a busy road but it isn't noisy because it is on the 7th floor (there's a lift). Highly recommended!