Just a quick update: After getting a 55" C7, I picked up a 65" 900E on Black Friday. After having the 900E for a week, I think I'm going to stay with it. I think the C7 is the better TV, but the jump from 55" to 65" is too amazing to dismiss.
I'd love to jump to a 65" C7, but that's just more than I want to spend on a TV right now (it's listed at $2700). I think I'm going to be jealous of the OLED crowd for a few more years. My hope is to upgrade to a 65" or greater OLED in a few years once prices have come down and the tech has matured.