Even if there wasn't any terrace, this apartment would be great for at least five reasons.
1. It's very bright (even when it rains!) as it's on the top floor.
2. It's higher than the buildings opposite, so you enjoy complete privacy.
3. It's really quiet: it overlooks a side street in a calm neighborhood, it's in a well soundproofed building, and there's even double gazing on all the windows.
4. The location is very good: you only need to cross the Ring to get to the heart of the Vienna (a 5-mn walk), but you don't have to put up with the constant noise of the busy and lively city center with its restaurants, bars, night clubs…
5. Cempaka is a very nice and cheerful host: she answered all my messages very quickly, and it was a pleasure to have a chat with her when I checked in.
In addition to that, the apartment is spacious, the bed amazingly comfortable, and there's plenty of place to put your things. Which is a sixth reason why I think this apartment is so great!