The only thing I can think to improve would be to lengthen the shutter to get some more motion blur. I feel that would make it feel more fluid, which for these clouds, would look amazing. It still is amazing though!
Isn't that what people said to 720p at the time? They said the contrary. Look how great this looks.
I don't disagree that 4k is pretty great and I can't imagine seeing much difference going better, but it will. That's the name of the game. It's what makes us better.
I would much rather see better dynamic range in cameras than anything right now though.