As everyone now knows, Sony's intent was to keep the 65" 850c artificially high in price until the last of the 2014 stock was gone, and then to drop it down to its real selling price, which is $2,599 USD. I would imagine that at least a few people who bought the 850b are a little bit warm under the collar to know that for just a few hundred dollars more they could have gotten a better TV. Still, that price opens up options that are worth looking into.
I'll be brazen enough to say on this board that if price is a determining factor the Samsung JS8500 is hands-down a better TV than the 850c. And it should be. If you scratch for every bug in the hen house you'll be able to find the 8500 for sale at "just" $500 more than the 850c, but its normal rebate cost is about $900 higher than the Sony. Still, the Sony may have a big advantage so far as purchasing strategy is concerned.
I know, you know, and Mother Hubbard's poor dog knows that refined and affordable OLED is not that far into the future, quite probably no more than three or four years. Spending monster dollars now for technology that is going to be woefully outdated in a few short years should make no sense to a Home Theater enthusiast. In its own right, I have no doubt that the 850c is going to give a solid performance, even with its shortcomings. At its price point this is a relatively easy TV to sell off in three or four years without taking a financial blood bath. Try doing that with the 930c or 940c. I don't doubt that by 2019 LED will be pretty much out the door, and everybody and the family parakeet will be making OLED displays. A top-quality OLED should easily retail for no more than $4,000 for a 65" screen.
All we have to do in the meantime is pretend that HDR doesn't exist. Not a problem, I'm sure, for most people in this forum. Certainly no one here is drooling at the prospect of seeing 'Star Wars Episode VII' in 4k Blu-ray HDR in Summer 2016. For sure, I know I'm not.