This is a very good hotel - well worth the money. I think it's relatively newly opened so some work is still being done, but don't worry: It won't bother you while you're there. The rooms are cool, bathrooms small but good. Breakfast is maybe a bit expensive but amazingly good selection of whatever you want. Friendly staff! The hotel bar at the roof top, Dachboden, is really cool with an amazing view over the city! Bar staff helpful and friendly!
You should definitely stay here if you're coming to Vienna. The best hotel experience I've had in a very long time! Location is top notch too!