What on earth was wrong that required that many replacements?
The two halves of the hard inner shell are held together by a slot/tab mechanism - one side of the slot broke. The belt clip snapped off the back of the holster. The retaining clip where the top of the phone snapped into the holster broke. Some of these things happened more than once.
I'll admit that this was a big departure from my prior experience with Otterbox. Things started off on the wrong foot with the Defender on the Galaxy Nexus because the Defender was designed for the Verizon variant of the phone, which is a little thicker than the GSM variant. With the case not snugly fitting the phone, the built in screen protector was not always in contact with the screen - making it difficult to interact with the edges of the display because the screen protector was held away from the display by the hard inner shell. I'm sure the curved display didn't help the situation either. I blame Samsung/Google for having two different form factors for the "same" device, but Otterbox gets the blame for designing a case for only one form factor, and not even being aware of multiple form factors until I told them about it almost 8-10 months after the devices were released.
Also, Otterbox's attempt to make the belt clip also serve as a kickstand resulted in repeated instances of my phone catching on something and pulling away from my body, leaving the belt clip in kickstand mode - ready to fall off the belt at any time.