I was a little leery about buying this because of the reviews but I gave it a go. I returned it after using it for 2 days. A lot of people complained about having problems swiping. I did not (unless it was off of the side which would technically be the bottom when in a game). While I didn't have a lot of problems swiping, I just found it annoying that Otterbox covered up the bottom bezel instead of making that part of the screen protector like they did with the BlackBerry PlayBook tablet. The holster was also just awful. The magnet wouldn't lock the phone since it was too far away and the phone could slip out because there was nothing holding it in on the bottom...it just slid around. While I don't usually use holsters, I noticed it right away while fiddling around with it.
I was also disappointed in the fact that Otterbox only has this case available in black. No colors, no variety...just black. A bit insulting. On a minor note, I would have liked the case to have a little window where it would show the BlackBerry logo on the back like Otterbox does for iPhone models. It would just be a nice touch.
I have seen reviews of people complaining about how the case is too bulky. It is supposed to be and that isn't something they should complain about. It is an Otterbox. But this case is definitely of a very poor design. Poor holster design, poor design for gestures, and the screen protector is a poor design for allowing so much dust into the case. You can just tell that Otterbox did not put enough care or thought into the Defender for the Z10 as they have done for something like the iPhone.
Cons: Low quality, can limit gestures, poor holster design, screen protector lets in too much dust, no colors or options