I like the 8K because I'm a detail freak. At this point, of course, I've only seen very carefully controlled demos. I would not like to pay for this detail with increased motion artifacts. Yes, I'm familiar with the viewing distance arguments, but I probably like to sit closer to the screen than most.

That said, Sony had an interesting demo at CES a couple years ago. They had a 2K, 4K with the full color gamut, and an 8K with the standard gamut. The question was "which picture looks better?", rather than "which picture has the most detail?". It was a hard choice between the 4K and 8K.