I'm not much of a Defender fan. Yes, the customer service is second to none, no doubt about it, but the Defender is imo a poor design. You put plastic around your phone then put silicone around the plastic. Then a few months down the road you take the case off and you realize that the hard plastic that sits right on your phone has scratched the device up in several places. Imo there should be some VERY thin silicone buffering in between the plastic and the phone, then made the outer silicone a hair thinner so no extra thickness is added in the case.
I will say this though, if you don't mind the scratches that you'll probably get to the case of the phone, the Defender does protect the device EXTREMELY well from bumps and drops. Personally, not my choice though. I'll probably have a BNIB Defender for sale here in the next few days.
I have a Commuter on my GS3 and I like it...now. my big complaint is that the Commuter has very little grip on the back of the case and will slip in your hands s bit. I've remedied this by putting some extremely thin (1/16" ) self stick foam grip on the back...it's designed for furniture or putting on the bottom home decor so it doesn't scratch tables or things like that. It's sold at any home improvement store for about $2.50. Now I love my commuter, I only wish it had a kickstand. Hopefully there will be an aftermarket kickstand available here in the next couple of weeks if the developer pulls through with them.