I've had my LifeProof case since Thursday. I got the black one, and I love it.
The thickness/size is the same as the OtterBox Commuter series, except the LifeProof is a bit longer at the bottom.
Overall, it isn't perfect, but it's as close as I've seen. I have no desire to ever take this case off or switch it out for another one, and that's saying something for me (a true case addict with an iPhone that's always dressed differently).
- Waterproof (obviously). I took it in the bathtub, the shower, and even put it in the sink to scare my friends.
- Slimness. It's smooth and pocketable, something my OtterBox Defenders lacked greatly.
- Appearance. I think LifeProof is an attractive case and fits the iPhone 4's profile very well.
- Durability. I haven't tested it yet, but many other owners have. Search YouTube. This thing lives up to its military-spec rating, definitely.
- Screen is odd. It has a bit of a contour shape to it, so the extreme lower and upper regions sit up off of the screen ever so slightly. It takes a bit to get used to, but isn't something unmanageable.
- 'Rainbow' effect. Sometimes, the screen of the case and the screen of the phone can touch in an odd way that leads to "rainbow" watermark looking areas, similar to the 3GS OtterBox Defender's original issues. My watermark spots come and go, but never stay there long.
- Noise. Extremely loud ringtones, such as the chorus of Adele's "Rolling in the Deep" can reverberate through the back of the case, since it is air and watertight. The noise can go up through the back if you hold the case wrong. It is hardly noticeable, though.
That's about it.
Overall, I love the case and it was well worth it.