In terms of totally kaput? Zero. I'm 99% sure the screen did end up breaking and she had to deal with that until she got her new one.How many iPhones did she go through, though?
Your link says the Otterbox is the best-all-around-protection for the 6s!The Otter box ones are supposed to suck for the 6s. When I got mine I checked out a round up Outside magazine did.
The 9 Best Rugged Cases for the iPhone 6 Plus | Outside Online
A couple of those are superior. I have the Dualtek one on mine, though it sounds like you are looking for something more overbuilt. I take it hiking and kayaking and shit no problem.