Hi,
I have just bought this TV and I have to say I am very impressed.
Initially I wasn't planning to go for a 4K set but didn't realise they had come down so much in price. When I looked into it, this and the Panasonic 50AX802B were the two that seemed to be best at the price point.
I looked at both in-store and they both seemed to have an impressive picture, albeit running the usual attract mode stuff.
In the end, the Samsung seemed to offer more for the money in that it has 4x HDMI v2 ports, superior smart features and has the upgrade port to give some limited future proofing.
While I agree that it is by no means essential to go 4K at present, if you are looking at spending good money on a TV anyway, why not go for something that is using the latest technology.
Still tweaking about with mine but watched Jurassic Park 3D on Blu Ray the other night and the upscaled 3D picture was fantastic.
JudgeC