My wife and I stayed in Elisabeth's apartment for a little over a month. We arrived in the middle of a heat wave topping 35C (95F) and she immediately decided to buy us a portable air conditioning unit and have it installed ASAP. This happened even though she was out of town at the time. It was really above and beyond anything we expected.
The apartment is in an older building but has been remodeled. The kitchen is new and well stocked, the bed is comfortable, and the whole place was very clean. It's located about 30 minutes walking from the Museum Quarter and 40 minutes from St Stephen's Cathedral. Public transit is much faster though and it's right across the street from a subway stop, which is great for getting anywhere in the city quickly. However, that also means the apartment is located on a busy main street. When the windows are open, it's a constant barrage of traffic noise and emergency vehicle sirens. Luckily when the windows are closed they are very good at keeping the sound out and it's much much quieter.
Overall it's a nice place to stay, especially if a little traffic noise doesn't bother you. Elisabeth will definitely do everything in her power to make sure your stay is a pleasant one. She is a super host.