I've had my OtterBox Defender for about 3 weeks and I love the protection it affords. My only wish is that the Defender had been available for my S5 when I got my phone so I didn't have to settle for the Commuter. I don't know why it took so long for the Defender to come out for the Galaxy S5. The Commuter I got when I got my phone started to deteriorate in the last year forcing me to get the Defender that I wanted in the first place.
Was a bit difficult installing the case but it protects my phone well as I have dropped it many times and none of the phone has been damaged in any way
Had to redo the fingerprint unlock after putting the case on. Good case, a little heftier than I need, but I suspect most people like the extra protection.