The apartment is about 2 minutes from Wilhelminenstrasse (Tram2, Bus 10a) or Familienplatz (T46, which goes past U3 Ottakring and arises into the city in an Eurovision fashion) on one of Wien's busy ring roads. However, it faces inwards to a sort-of garden so you do not get the fumes or noise. There are supermarkets adjacent. The building is somewhat tired (zither music was running through my mind) with strange doors giving it an historic vibe. This is exactly what one wants when staying in this part of the city as Ottakring is full of 1890-extension buildings (which are grander than those in Wieden).
You can have a late breakfast in the grand, and traditional, Café Ritter in the next-west street (Ottakringerstrasse) and use the opposite ice café for large and cheap feast after a hard day of touristing. The next-street west is Thaliastrasse which has lots of food places on the way up to the U-Bahn. I had a large and cheap pizza at the Italian (but you may have to be prepared to wait 20 mins for service).
The apartment has lots of power points and a well equipped kitchen with a toaster, microwave and pod coffee maker (the host kindly gave me some). The WiFi runs at around 13Mb. Due to DB stranding me at Frankfurt, I was a day late arriving: the host was very understanding.
There is a large internal gas boiler but no carbon monoxide detector. As Zaphod would say, a portable detector is, like your towel, part of your gear; otherwise, despite the boiler having lots of service certificates, you might care to keep the windows open. Hot water is supplied from this bit of kit, but experiment shows that you need to fire it up before having a hot shower. You do this by turning up the room thermostat so getting the heating going for around 20 minutes (and opening the windows!).
Altogether, a reasonable stay with good U3 and T services to get you where you need to go. The lack of a carbon monoxide detector is a bit of a negative, and I strongly recommend provision. Nevertheless I would return if I were in Wien again.