My wife and I stayed here during a recent trip to Vienna and Budapest and are very glad to have done so.
First off, the location (especially for the price) is great. It is about 1500m to almost all the old city sights. We walked everywhere, and nowhere seemed very far. The neighborhood is upscale university, so a lot of young people around (and areas where they go) but without the noise typically associated with a university area. Plenty of cafes and such nearby as well. Since it was during Christmas time, we could walk to two of the main Christmas Markets in under 15 minutes.
THe hotel its self is also great. The Staff is friendly and accommodating. They have their own parking, but if it is ful, you can use the nearby public garage for the same price (it is next to their private one, so very close). The hotel is glean and well maintained also. Our room was spacious and overlooked the university and main road but it wasn't too loud to sleep with the window open. We had plenty of room and found it quite comfortable. THe bathroom was nearly new (looking) and also much larger than is normal in Europe with a double-sized shower and "rain" shower head. THe additional medicin cabinet was nice for my wife to store her stuff also.
We had breakfast here one morning, and it was very good. THough a bit expensive (compared to a bakery, I suppose) it is very well appointed and worth the price they charge. The breakfast room was comfortable and the staff attentive. It is worth noting, that if you do not wish to have the buffet (15Euro, I think), tehy do have items to order, such as omelets, wich are well priced (I think one ran about 5 Euro), so there are cheaper options for those on a budget.
In the end, I would gladly stay here again and it would be my first choice if returning to Vienna.