If you've ever shopped for an iPhone case (or an iPod case for that matter), you know that everyone and their brother makes one. I even see them in the supermarket. With so many options it's difficult to tell the useful from the junk. After a month of real-world use, I can say that the Otterbox Defender is an example of the former.
First, what it's not. This isn't a sticky, gummy film or decal that's going to leave gunk all over the place. It's not a neoprene sleeve that's difficult to apply and remove. There's no silly logo that's going to embarrass you during a meeting.
Nor is it for everyone. The Otterbox Defender is for the active user who is likely to drop their iPhone, due to strenuous activity like biking, running, climbing or parenting. The case is very rugged and sturdy. But I'm getting ahead of myself.
Out of the box there are three pieces: Front, rear and the silicon skin. Assembly is simple: Pry the plastic pieces apart, slip the iPhone inside and press to snap. From there, just slip the skin in place.
All of the little bits line up perfectly (almost*) The headphone jack, hold button, home button and dock connector port are accessible. I was worried that the screen's responsiveness would be impaired, but that wasn't the case. It behaved exactly as if it were naked, though the feel was different.
The real test would be to see if it's as tough as it looks. I went out into the parking lot and dropped it from waist height (I'm 6 feet tall). No problem. Next from shoulder height. It didn't even blink. It bounced, but didn't blink. Finally, I handed it over to my kids. While the added bulk was most noticeable in the hands of a toddler (anyone who's held a Newton 2100 has a point of reference), it isn't meant for a toddler, so that's OK. The kids dropped it, pounded on it (iChalky gets them especially wound up) and even spilled half of a juice box (don't ask me how many ounces) onto it. The case took all of it and the iPhone kept on ticking.
*First and foremost, the mute button is inaccessable with this case in place. In fact, there's a notch of hard plastic directly over it, so no amount of forceful pressing will get it to flip. That's an unfortunate oversight.
Of course, it adds some bulk. I didn't mind at all, but some will. I'd rather have the peace of mind that the phone is secure than quabble about a few ounces. Lastly, it doesn't slip in and out of a pocket with the near friction-free glide of a naked iPhone. It's no problem with bulky jacket pockets, but requires two hands (one to extract the phone, one to hold the pocket in place) with jeans.
Finally, you can't use the dock with the case installed, but it's no problem to simply connect the cable.
TUAW Buying Advice
If you're in the market for a hot pink Hello Kitty case to show off at the next PTA meeting, the Otterbox isn't for you. If, like me, you want real protection that doesn't interfere with function (except for the mute button for some reason), consider the Otterbox ($49.95US). It's very tough, looks cool in a military hardware kind of way and stood up to the punishment of two rug rats.
Sometimes, even I can't do that.