Because Target has it for $470, think I'm gonna go with a 50 inch version of the Samsung KU6300-
http://www.rtings.com/tv/reviews/samsung/ku6300
It's not perfect of course, but based on the many reviews I have read, it seems like the best bang for the buck. Biggest positive is it is great for gaming with low latency. Biggest negative is that it isn't "True" HDR. It supports HDR 10 but the TV's color gamut can't quite hit the full range to get all the benefits from it. From what I've read though, it is still much much better than SDR sets, so I should still be relatively impressed coming from my 40 inch 1080p lol. Oh and the upscaling is very good which is a nice plus, considering I don't have a UHD Blu Ray Player (thanks PS4 Pro) so I'll want my regular Blu Rays to look good on 4k.
Obviously I could spend hundreds more and get something much better, but I think this is the best all-around compromise, a happy medium where I get 4k and a taste of HDR goodness whilst not breaking the bank.
If anyone thinks I shouldn't, let me know why!