Interesting on case usage. I'd say virtually everybody I know with an iPhone has it in a case, but for other devices it's maybe 20% of people I know who use one. All anecdotal, and every mall I go in has a hundred shops selling them, I've just always wondered who's buying them

I've never used a case on any of my phones whether iPhone or Nexus. I did use the iPhone 4 bumper they gave out because it was free and I liked the little ridge that let me lay the phone face down.

I'm using a bumper-style case myself just because it came with the phone, and the phone has a glass back and razor sharp edges which is really just bad design.