I don't think you are not going to be able to work any of them underwater..its not a function of the case, its a function of the screen being capacitive touch...
I have a feeling this is one reason that the "Plus" (audio increase) button on the side of iPhones now works as the "shutter" button.
Isnt perfect, but it works, if you plan to do a lot of underwater picture taking I would recommend getting one of those sweet durable nikons. For shallow water, daily exposure, and pools, lifeproof is awesome. Long term exposure or depth, they seem to be hit or miss... totally a function of how well you put it on and how often you take it off (these kinda things will wear).
My buddy lost his phone, bottom of Annas Pond in Waimea on the big island, 6+ feet deep......6 months later he got a phone call, someone found it.....
My phone, in a pool for about 30 minutes at around 4 ft, got some water in it....not enough to hurt it at all, but I had to take the case off.