Our stay in Vienna at Plamen's was great! The apartment is exactly as in the pictures, new, cute, spacious and clean. Also, it's location is great (2 metro stops away from the cathedral). Plamen replied to my messages within minutes and had no trouble being flexible with check-in and check-out or with letting us have an extra guest for the last night. I really really recommend this place and I'd stay there again if I ever come back to Vienna :)
The only negative remark I can think of was the lack of shampoo and shower gel the day we arrived, which was a bit of a bummer as we were counting on it and couldn't buy it until next morning. We left there the shampoo and gel we bought so I guess it shouldn't be a problem for next guests ;)