I was using the Ballistic case, which is a really nice case but my local AT&T store got some Defender cases in so I had to grab one. I'm glad I did.
Upsides include:
The case fits great, only adds about the same amount of bulk as the Ballistic and the holster is nice. Great protection and the "new" silicone that Otterbox uses has
more grip and has
less lint attraction.
Downsides include:
The built-in screen protector does not "lay flat" onto the screen itself, giving a "bubble" feeling. The holster uses two points of contact on both sides making a little more difficult to remove. Plus, the Defender is pretty pricey.
For anyone who usually removes the built in screen protector, like me, I found it to be pretty simple as it just "pops" out with a little pressure and then the glue strip comes off just as easy. I have included a pic of it in the attachments.
I have also attached some pics showing the bulk compared to the Ballistic and the holster's "points of contact", as well as some other random shots of the case.