Well, after lots of waiting and anticipation, I finally received my LifeProof case four days ago, and it's been an interesting experience. Initially, after the excitement of finally getting it, I left it sitting in the box until I had sufficient time to install it properly.
Good thing, too, because it wound up taking about an hour. That's because they have instructions online, and a warranty extension that requires you learn about the case and answer ten questions correctly. I also had to reinstall it twice after finding a tiny particle or two on the screen.
All in all, I think it's a really smart way of making sure users know what the hell they're doing and not just winging it. The case's correct function (i.e. being submerged in water) requires putting the damn thing on right and knowing how to avoid problems. You have to clean the phone really, really well. That's cool with me because I'm a nitpicker about that anyway, but I like that they included a cleaning cloth. Keeping the seam absolutely free of particles is important for ensuring that the case stays waterproof.
So, I install the case. Cool. Now the first thing I notice is the screen protector. It's raised above the screen and looks plasticky. "Wtf," I'm thinking, "this case sucks! I'm sending it back!"
Turns out, after some more reading on the site, there's air that gets between the screen and cover, and it needs to be pressed out. I subsequently discovered that it's easiest to do when installing the case (I think proper installation is super-critical and will affect how it performs). Boom! Suddenly my case became fricking awesome again. I've been using it for the past few days, and I find myself liking more and more as I use it.
The thing is super-light, is easy to get into (and out of) my pocket, isn't bulky and feels solid. It really feels good in the hand. As far as screen usage, you'll probably hear groans about it not being as good as the naked iPhone, but it's an adjustment and you get used to the slight tactile difference pretty quickly. Also, unlike a lot of screen protectors (i.e. the Invisible Shield), the screen looks just as vibrant, without any weird patterning or distortions. It's pretty goddamn cool. Oh, and the case comes with an adapter for waterproof headphones, which is also cool...although I honestly don't ever see myself swimming with my phone...not intentionally, anyway ;-)
So there you have it, folks! I'll attach some photos for your perusing pleasure. Feel free to ask me any questions. And no, I'm not affiliated in any way with anyone, FYI.