Glad you like the Otterbox Defender. I thought about getting it when I bought my HTC One, but I decided to get the Otterbox Commuter, and I am very happy with it.
The Otterbox Commuter case fits like a glove and provides great protection. Since I got my HTC One, and the Otterbox Box Commuter case, I have dropped my phone a couple of times and the case has protected it.
I have to say that so am very happy with the quality and build of the Otterbox Commuter case.
"No matter where you go, there you are!"