Get the 4K. Most people who argue against it probably have not owned one. It is 100% worth it. Even if there is little 4K content available, 4K TVs upscale current content and make it look a lot better.
What's the price difference? If it's within 30% or so, I'd get the 4K for future proofing. And also, who knows, the TV may end up on your desk as a computer monitor/TV in a few years, so having the extra resolution would be cool.
Also, my camera shoots 4K video, and even on my 1080 television, the play back is much improved. As far as watching anything goes, I download everything since I gave up actual television years ago, and I just run the hdmi cable from my laptop to the tv. Works great.
That's not what I meant. It's just like the "Windows vs. Mac" argument. Everyone will give you their opinion, which is great, but if someone has not actually owned both, where is that opinion coming from? Just my two cents.