Petra was a lovely host - we were greeted with a nice note and bottle of bubbly. She was super responsive when we had questions and concerns. The apartment was just as described (plus it has a nice shower with multiple jets and tons of towels) and the view of the cathedral is beautiful at all times of day and night. It's super walkable to everything.
The only downside to this central location is the noise - the apartment is in between two very active bars on either side so it's super noisy until 2 am and then it starts back up again at 6 am when the beer kegs are being replaced and the cleaners come in (backing up trucks with loud beeping, rolling kegs,talking). We stayed in late August so it was always hopping. I would highly recommend this place in the colder months when people aren't drinking on the patios below the apartment or if you're a really sound sleeper/comfortable with ear plugs.