I had a perfect stay at Albert's place. It is clean, well equipped and convienently located. During Check-In Albert provided me with helpful tips on how to get along in Vienna and which places are worth seeing.
Bear it mind that the flat is situated in an old building - at times you could hear the neigbours talking. Also it is placed on the ground floor - sometimes you could hear the noises from the street. However I did not have any problems with sleeping at night. I would be happy to be able to stay at Albert's place again - the flat has my recommendation!