We liked our vacation at Franz 2 a lot!
If I remember correctly, we were the second guests in the apartment. Everything super clean and nicely prepared. Everything is designed with lots of taste and high-class materials (e.g. parquet, high-quality and tasteful equipment for the kitchen). The location feels very spacious. Landlords invested generously in the location.
The hosts were super friendly and eager to make our stay as convenient as possible (e.g. early arrival time, fire place, recommended restaurants).
The only point of critique is noise related. A rather lesser frequented Bundesstraße is relatively close. The new windows help out a lot in this regard, at least when they are closed, but for people who are easily bothered by noise this might be an issue in one (1) of the rooms.
There are a few sheep our sons enjoyed a lot being around.
There are several nice hikes and bike trails very close by such as Alpkönigblick. Eistobel is a 10min drive. Alpsee is not very far. Neither are Kempten nor Isny. There is a very similar apartment on the same floor, which seems an optimal solution for two families. Landlords live in the same house so they are accessible. Washing machine is in an extra room outside the apartment, which we found optimal.
All in all: Highly recommended location.