The flat is clean and the terrace is lovely.
The building seems to be brand new, so is the flat.
The bedroom is ok, with unfortunately too little space to put our stuff.
The bed, especially the quilt, is quite small and the pillows are not pillows to sleep on, rather cushions (the ones you would put on a couch) - it could have been a better place to sleep.
Katharina was not here but her roomate explained us everything.
The subway line U3 is close to the flat and it is very useful if you come by bus (Erdberg station).
It also takes you to the center very easily (~25 min).
To sum up : a good flat if you don't need much, reach for a relaxed atmosphere; and not too far from the center.