I've used Otterbox in the past with success, but I had chosen a different brand for protecting my iPad mini 3. It worked great, and at the time of purchase it was a great value. After upgrading to the mini 4, I checked online to determine which brands were getting the best actual reviews. After a few design changes by others, it became apparent that Otterbox had 'stayed the course' more, and it was pleasing most who posted comments. One brand was saying that the protection case for mini 3 & 4 were interchangeable, and I knew that wasn't totally accurate.
Best Buy had a superb sale at the time I was looking, so that sealed the deal. It was mailed to my home, and I found it extremely easy to install my tablet into it, and that it would offer the desired protection. The buttons were responsive, and all outlets lined up correctly for things like headphones and chargers.
I've [so far] had zero challenge with the built-in screen protector. I'd considered removing it and adding a ZAGG, but that has not been necessary at all. I'm pleased with the current experience.
I dropped my previous iPad only once, and I hope that I never ever drop this one, but . . . if that were to happen, I personally believe I'm totally covered for impact protection.