The location of the place is amazing - 5 minutes walking distance to Stephansplatz which was amazing, and on top of it a metro station is just across the canal and a tram station right outsite of the building.
Overall a very pleasant stay. The room is just as described, small but clean and has everything you might need for a 3-4 day stay in Vienna.
The beds were more comfortable than we'd expected, however the only we had a big problem with the pillows - one was impossible unusable.
The communication with Dan was impeccable, a month prior to our arrival we got a detailed explanation on how to check in.
One thing that we found to be missing were tips of places nearby - local market, dinner place etc, or even a public transport map, but we managed either way.
To conclude, I highly recommend the place, primarily because of its location.