My "Chinese 12k" arrived with one quite smooth side (guessing somewhere below 400 grit but sure) and the other side I started to lap with 400 grit and gave up after I realised how deep the scratches were on either end with the middle being smoother than the aforementioned smooth side. One day I'm going to take the stone through the grits and probably polish it off at 1k or so.

My stone leaves a noticeably nicer edge to my kamisori than the Norton 8k. As for straights, I only used it once, briefly and when I very first got it, on my straight and it also improved that edge too.

YMMV but I really like mine.

Cannot comment on the lower grit stone.