This was our first trip to Munich and we had a wonderful time:D
Annette and Ulf were extremely helpful before we even got there telling us which tickets we needed and the S-Bahn we should take from the airport (Tip: get the 4 day tourist one, you get discount to attractions too and unlimited travel on everything!).
The apartment was huge for the two of us! The kitchen has just been re-done and is lovely, not that we used it much as we couldn't resist the Bierkellers and amazing restaurants Munich has to offer. The bed is super comfy and the whole place was lovely and cozy. The bathroom is great with a good powerful shower. The whole place was lovely and clean and very quiet.
It was only a 5-10min walk to the S-bahn and about 15mins in the centre, they run every 10-20mins, we never had any issues. There are shops and restaurants closer to the apartment but we always ventured into the city as it was so easy.