The Otterbox Commuter for the Moto X has been a great case for this phone. It doesn't add a lot of bulk and has done a great job of preventing damage. I drop my phone a lot and I am sure this case has saved the phone on several occasions. I always keep an Otterbox on my phone!
It's pretty good. Gives you a nice grip and gives a feel of protectiveness like it should.
The only thing I didn't like is how hard it is to remove it. It doesn't take a lot of strenght, but it is hard to get the correct way of removing it without feeling it will break.
This case is great. Not too bulky and doesn't completely cover the phone. I've used friend's phones with the full Otterbox case and didn't like the front piece that covered the phone. It made the screen feel unresponsive. While the Commuter case doesn't offer the same protection, I'm not concerned with that and love having the open front.
My only complaint is that the protection on the volume buttons is difficult. Either it doesn't line up quite right with my phone or is just too bulky but it is nearly impossible to adjust my volume with the side buttons.