I hereby swear allegiance to incipio cases. I can fully attest to how well they protect the phone, specifically the Frequency case.
I had accidentally tossed my phone out of my car trying to swat at a moth that flew in as I was trying to set up bluetooth parked in my garage (it's a funny story *now* - the door was open, indoor light was on at night...). The phone FLEW a good 2-3 meters away and went as high up as 2 meters off the ground, and I let out a gasp that must have woken up the neighbors. It fell on smooth concrete.
Absolutely *NOTHING* happened to the phone. Nothing. Not a scratch. Even the case looks unscathed. The device works perfectly. This happened the very day I got the phone and I've been on vacation since then (currently in Paris, woohoo), and I was a bit scared that the camera's inconsistency was due to the "accident", but reading on the forum leads me to believe that it's a normal thing. I can still take amazing pictures, as I'll try posting soon in the picture thread, but sometimes the lens just won't focus properly on what should be a pretty straight-forward picture (happens about 30% of the time). I've taken a good 200+ pictures since then, so I know it's fine. I haven't had any update pushed through, either (HTC One Dev edition)
People, Incipio Frequency. I can't recommend it any more than what I'm trying to convey in this text. That case saved my phone. It has great feel in hand, protects the front of the phone from contact, easy to pull out of my front pocket (won't stick), and looks good to boot. If you're still undecided or aren't fully happy with what you have now, give this a shot. You won't regret it.