My daughter could not sleep on the bed, due to how bad it was (hard, old, generally not comfortable). Our bed was also making noises as soon as one would turn. A pity, and hopefully easy to solve, as everything else was lovely.
Although the location appears far on the map and might turn off some people, it is in a lovely area surrounded by vineyards, and with quick access to attractions such as the Mercedes museum or the Cannstat Fest.
The owners were kind enough to give us a very large room to accomodate us as a family. It was equivalent to very large suites in upscale hotels, with large sitting room area, a small library of books, plenty of space.
The owners were very kind and helpful, and breakfast was lovely.