Not to mention the Otterbox is ugly and reduces display quality with the crappy matte screen protector.
The LifeProof will include instructions on how to test the integrity of the case before placing your phone in it. Last I heard they won't be offering a warranty for the phone itself, and I don't blame them. I can't imagine how many idiots will take it SCUBA diving to 60ft and then complain that LifeProof ruined their phone. There is no proof to show that the case was used within its limits for them to offer a replacement due to defect.
And you can't put an otter box in your pocket it gets stuck. Also as long as theres a way to test it before you put a $300 phone in the case that'll be good enough for me.