I myself got a IWC top gun which is also in made of ceramic.
I found the problem is the watch can be scraped over from other metal which would leave marks on the watch which is really hard to get it out.
I am not sure if that would happen to the 317 owners. I am still waiting for my 317 to come in.
Is there any good way to clean ceramic watches ?
Oh, i also figured ceramic watch cant be polished at the service center.
Best Regards
FAi