I've commented on the otterbox defender series case before. I've got one on my Dinc. Yes the defender series will bulk it up, with the outer hardshell and clip but guess it depends on your lifestyle. I'm a mechanic so I need something that can withstand getting dropped or inadvertantly laid on, etc.
The defender is like a brick **** house, it just doesn't get any better protection wise. The nice thing about it, is if I take the phone all the way out to just it's core size without all the protection, and wipe it down, you wouldn't know this phone was not brand new, it's mint condition, thanks to the otterbox, and it has been dropped on the otterbox at least 5 times.
The commuter series would be a lot smaller profile if that's what you are looking for....
I'm glad to see OB has their act together on this and released a case for it, it actually took them a while to release one for the og Dinc..