Nikola's apartment is fantastic, and excellent value for money. It is located just off a shopping street and about a 3 minute walk from a U-Bahn stop which was very convenient. The apartment has everything you need and more - a huge 3D TV with Netflix, a well equipped kitchen with an oven and an induction stovetop, 2 double beds (one is a couch but very comfy), etc.
Nikola was extremely helpful before and during our stay. He would reply to our questions within minutes, and he very nicely stocked the fridge with chocolate and alcohol! I would highly recommend this apartment for anyone visiting Vienna.