We had a great time at the DO&CO hotel in central Vienna. It is perfectly located (overlooking Stephansplatz and the St. Stephans cathedral, right in the heart of the inner city.) It's an unusual place: built within the historic and modernistic Haas Haus. The rooms are highly designed and trendy, with advanced electronic features which are somewhat hard to use. But at the same time they're extremely comfortable,with great beds, glass-walled shower with rain head, Bang and Olufsen plasma TV.
We watched the street entertainers in the square below from the comfort (and quiet) of our bedroom.
Storage spaces for clothes(drawers especially) were in short supply.
The youthful staff were accommodating and helpful. Our dinner in their DO&CO restaurant was one of the best of our trip. It was lovely to have an alternative to the usually heavy and calorie-rich (though often delicious) Austrian cuisine.
We didn't include breakfasts in our hotel price, as there are many reasonably priced breakfast places in the immediate area.
Highly recommended as a centrally-located and unusually designed hotel. Check out their website before booking to make sure that this is what you want.