We stayed at Mirella's place as 6 friends of a 'certain age' who love to travel and visit different cities.
The apartment is even better than the description. It is extremely stylish.
It was very clean and comfortable and the rooms are huge. It was a pleasure to sleep in the spacious bedrooms in very comfortable beds. The kitchen is well equipped although, to be honest, we ate out at every meal time.
The location is very good - we walked to most places and caught the U1 line (nearest station about 10 minutes walk) for sites that were further away such as the Danube Canal and the Prater. There are some good cafés for breakfast in the area and some nice restaurants.
Mirella was very easy to contact and always replied to my queries immediately. She was very helpful.
The area is beautifully quiet - in fact the only noise we heard was from a nearby bar on Saturday night although it was minimal and finished early.
The only possible issues were the window blinds which were not blackout blinds. Two of our party like to sleep in total darkness but as it happens it wasn't an issue at all as the sun does not shine directly into the bedrooms in the morning. The other possible issue was that there is only one actual shower cubicle - the other room has a bath with a shower attachment but we managed with no problem.
Overall, we had a wonderful stay in Vienna and I would have absolutely no hesitation in recommending Mariella's apartment as a most comfortable base.