The "Blue Danube Hostel" is really just a collection of apartments, not a hostel. Aside from the misleading name, the apartment I was given in the "Blue Danube Hostel" was excellent. My room was very large, and shared a very large kitchen with one other room. The location was excellent, and Sandor, the owner was extremely friendly and helpful.
The only problem I had was finding it, since there is no sign for it, and the building directory doesn't have it listed under "Blue Danube Hostel" but rather under th eowner's name.