I very happily stayed in Heidi's studio apartment 3a for 2 weeks. For me it was a great place to work and hang out, the bed is comfortable and there is enough space for 1 or 2 people. The clean studio with Scandinavian flair is located in a typical Vienna Altbau and has lovely high ceilings and old windows. The bathroom is on the smaller side and the kitchen/entrance hall is properly equipped.
If you are looking for a good place to explore Vienna from, this place is great. Perfectly located between the city centre and Vienna forest. No distances take long in Vienna, public transport is fabulous. Heidi is lovely, helps where she can and is easy to reach via phone and email.