Personal Experience
Is OtterBox the brand to go with for drop protection? That's the impression I've gotten, but is that true for all their cases or just the heavy duty ones?
Also, have you guys seen the shipping rates to Mexico? 500% duty/taxes.
Edit: Do the cases cover the speakers at the bottom?
The previous Defender case had a covering for the speakers holes so that they were protected from dust, but could still function. I can't speak for the other models as far as a dust covering, but the rest of them would certainly have an opening for speakers.
My experience with Otterbox cases has been pretty good. I work as a Pro Audio installation technician, and regularly work on construction sites. As I regularly move around heavy boxes and equipment at both finished and new construction sites, I wanted something durable and dust resistant.
The defender case for my 3G has more than adequately performed. While it is not 100% dustproof, if you close the silicone plugs, a large majority of dust remains out of the case. I regularly crawl around under stages and booths covered in dust, and my phone case has been covered in dust with my phone no worse for the wear as long as it has been properly close up.
I have dropped it, and had multiple boxes and pieces of equipment pressed into my pocket with the phone in it (in the case) and while it has been inside the otterbox, no harm has come to it. (Unfortunately, I can't say the same for the phone when I had it taken out of the case.)
The new ones for the iPhone 4 look slimmer. I had a hard time getting the older version out of my pockets since the silicon cover had some definite resistance against my pocket. Can't tell you how many calls I missed that way.
That's my experience with the "heavy duty" one. The commuter doesn't have the dust protection, or dedicated screen protector built-in (though they give you one for the phone itself I believe), and the last model I know little to nothing about. It's silicone only... not sure of the thickness.
Hope this helps.
Mike