I wanted to share my experience too with a ZF aquanaut I acquired recently.
It's keeping accurate time and it's running well while worn. However, while off-wrist at night, the movement sometime stops randomly, after 2 or 3 hours. In the morning, if put on the wrist, it starts working again. For 3-4 nights in a row there are no issues, then suddenly it stops. It's very strange and I was wondering whether any other people here in the forum have experienced the same issue.
I'm currently in contact with the TD to resolve the issue, but for now I've got the usual reply like "wind it manually, tap HARD on the back of the watch and try it for another 5 days"