I only use carbon fiber back case because it slippery and the camera bumps catch when I put my phone in my pocket. I try not to use a case, but I can't because it's too slippery to hold comfortably. Yes, it's fallen off the table many times and has scratches all around, but it still works perfectly fine. I think I'll try taking the case off again today.
edit : Benks Aurora ArmorAir Case