I’ve been using the NewerTech NuGuard KX Case for iPhone 6s, 6s Plus on my iPhone 6s Plus since I got the 6s Plus (also on the iPhone 5s before that)
I’ve dropped the iPhone 6s Plus (what a clumsy form factor) enough times and hard enough that I’m pretty sure the NuGuard KX case saved me from an expensive re-buy, so the case has proved its worth to me.
But one thing that has been an annoyance is the on/off button being difficult to activate with the case over it, and difficult to find by feel in the first place. So using a knife and scissors, I fixed the problem by removing the case that sits over the on/off switch. The case is sturdy enough that cutting out a hunk of it to expose the on/off switch is no problem.
As an unexpected bonus, the hole cut into the case provides a great finger slot for a sure grip. I am now very pleased with my “custom mod” NuGuard KX Case.