We've been at Elena's place for only one night, but if we come back we'll try to stay again!
Elena's flat is just perfect: it's very modern and beautiful. It's bigger than you think. All furnitures are comfy and really nice. There are all needed utensils too. The flat is in the perfect location - in nice, quiet area. Tube station (U-bahn) is 8 minutes walk and you've got only few stops to the city centre or breathtaking Schonbrunn palace! Oh, and also Elena offers you a spot for your car in the garage under the building for free which is great, having in mind quite complicated parking system in Vienna
Truly, 5* place :)