I have the c1 65 inch. It's very good. I haven't fucked with a lot of the features of the TV and i haven't checked calibration (although my wife tells me that the guy we payed to mount it may have calibrated too.)
I'm going to be honest. While shopping, most of these high end TVs look pretty close to each other and unless you are looking at them side by side simultaneously, chances are good you wont' really notice the difference between one TV and another of equivalent price. And if you notice differences, they may come down to calibration rather than actual tech differences. Many features, like HDR, may change the picture in ways that are suprisingly subtle given all the hype, but IMO don't necessarily make it better. The difference comes down to taste and a lot of those things kind of fade away from your mind when you've had the TV for a couple of months. Content is king, so if you're watching Billions does it matter if your TV has all the latest doodads? not really.
That said it's a good tv. I don't regret it. Major caveat is that default sound SUCKS on these things so you must factor in the cost of a soundbar at least.