We stayed at Ingela's apartment in the beginning of April with 3 children ages 11, 8 and 5 mos. Ingela was very friendly and helpful.
The apartment was cold at first but we adjusted the AC and it became ok. However, I would recommend some slippers or warm socks as the apartment is on the ground floor.
Kitchen - there was everything that you need for cooking (utensils, pots, etc) as well as some basic like salt, sugar, teabags. Nice stove and microwave.
Living room - very cozy, also served us as a dining room. Comfortable sofa, armchair. We didn't really watch TV but there is something with the volume - even on the max it was like min. But Ingela has DVDs so the kids watched a few and the volume worked fine in that case.
Unfortunately, we didn't get to enjoy the terrace due to the chilly weather, but children did go out once to play "who-blows-out-all-the-candles-at-once" game =)
2nd Bedroom - limited space but enough for sleeping, however, the closets are quite spacious. Children enjoyed playing on the bunk beds - creating some kind of a club/tent.
Master bedroom - spacious, light, very roomy closets. The mattress is too soft for my liking but generally serves its purpose. The blinds can be shaded which is nice for sensitive sleepers. We used the bunk bed for our baby instead of the crib, as with the crib you needed to bend down to put the baby in, which is tricky in my case as I always tend to wake him up. So we brought our own mini-mattress with sides (not sure what it's called).
Bathroom - I liked the washer/dryer the most as we had to do laundry for our kids. Otherwise, nothing special. The good feature is that the toilet is separated. Location - very central! On the map it looked like a lot of walking to the central Vienna, but upon arrival I realized it's easier to walk rather than use underground (the closest Ubahn is 2-3 mins away, or there's another Line 5 mins away). We walked to MariaHilf, StephanPlatz, etc. Even with 3 kids I was able to get around very easily and relatively fast.
Unfortunately, there is no supermarket very close, so we had to walk a little, especially to find diapers which for some reason were only sold at DM (cosmetic store).
There is a Citybike station very nearby as well for those who want to take a bike-tour instead of walking. If you return the bike within an hour, it's free of charge, then you can take another bike right away.
Note: there is a little staircase for those who will be visiting with the strollers, not too bad but tricky. Oh and to turn on the light in the corridor you need to press the red little round button (we couldn't figure it out at first and ended up ringing the neighbor's door as it looked like a standard light switch).