Great advice. I've had four "waterproof cases". Three failed without warning. I work around saltwater so I thought it would great to have a case that would allow me to use my phone without taking precautions. I had the first case about 6-8 months with a perfect record. It had even gotten accidentally submerged a couple of time. Then I picked it up to use it after it got some light spray on it. The screen looked strange. I immediately knew it was water so I ripped the case open and dried the phone off. A mysterious pin hole had developed in the Gore Tex covering the ear speaker hole. Had my phone gotten submerged it would've been ruined.
The second failure happened when I was off of work cleaning come fish. My phone rang I answered it with absolutely filthy fish gut covered hands so I stuck under the hose to rinse the screen off. Again I immediately noticed water flooding underneath the screen cover. Same deal as the first time, ripped it open, dried it off, again luckily the phone still functioned.
The third was a cheapo knockoff of the most popular waterproof case. No hidden failure there - the screen tore away from the plastic. I never trusted it enough to fully submerge it but it was 1/8th of the genuine case's price.
My 4th waterproof case was a tank. It turned my phone into what seemed like a 5 pound brick. I carried it for awhile but upgraded from an iPhone 4 to iPhone 5S so no more giant brick case. I never had any water issues with it but the size and cost were a definite tradeoff.
Eventually I gave up on the idea of a waterproof case as an everyday carry. The tradeoffs just weren't worth it - the not knowing if today was the day they were going to fail, the cost (from $10 to $100), and then muffled sound quality that got worse the longer you used the case. I went back to a "rugged" case - Pelican Voyager.
