Vienna is awesome. We really liked it. The apartment though was a bit of a disappointment for us. In my opinion the price is way too high compared to what you get.
The house where the apartment is was under construction. Of course nobody informed us about that. It was noisy.
The interior of the apartment is very cheap. The walls are dirty and the atmosphere is very cold. They put IKEA furniture in the rooms and some empty picture frames on the wall and that's it.
You cannot heat up the kitchen so there it is always cold (rooms are ok though).
The apartment is a bit dark.
And it was a bit dirty (shoe print on the shoe cabinet for example).
I strongly believe that you can find better value for your money.