Yes, I have a Samsung JS8500, which was their flagship flat screen 4KTV last year. I love it, and am definitely happy I sprung for a model that supported HDR. As a first year implementation, it's amazing and I can't imagine what it will look like on displays a few years from now, when the tech is really fleshed out.
There are a lot of TVs now that support HDR10, in varying nits and panels and everything else that confuses the buyer as they research. I think I saw a 50" set that supported HDR for $500 the other day, which is a great price. Definitely try to look for a demo next time you are at Best Buy or wherever.
From what I understand though, there is no benefit of HDR on a TV that doesn't support it - the information just doesn't get sent to the television, and the movie just looks "normal".