I picked up the UHD package here in Australia the other day, which comes with the black and white bluray. I played the UHD on my Panasonic 820 UHD player, and did back and forth comparisons with the new bluray on my Oppo BDP-93.
I can only agree with Mr Harris - there is some weird stuff going...
I haven't seen the 4k disc, but going from the screencaps I've seen, I feel like the "grain" on this 4K is goosed up or sharpened in some way. I doesn't look natural.