We had a really pleasant stay in Sascha & Marina's apartment. The place is very comfy and you'll find everything you need in the kitchen and the bathroom. The location is great - it is a little far from the city center, but you can easily reach it by the vienesse public transport. The tram stops some 5 minutes walking from the front door. The self check-in was flawless, as was communication with the hosts.
As someone mentioned, the street outside can be pretty busy, but a pair of earplugs will do the work :))
To sum it up, I'd definetely book again! :)