Just flew this route a few times since we were able to clock 70k Mileage Plan miles per RT. Overall, I was pretty impressed with Hainan's business cabin and found the free limo service super valuable both stateside and in China. I'd never considered flying them until they ordered the new 787-9s, but I'd do it again in a heartbeat. I will note that we always got the new Dreamliner seats on the outbound but never did on our returns. If you do fly Hainan, make sure you check the seat maps and are on a 1-2-1 config rather than the old 2-2-2 cabin.
I put together a write up since none of the major bloggers have written anything about the updated Biz product.
I'm booked next month on old 789 route BOS-PVG but will be switching to BOS-PEK for the A350. I would head down to NYC instead and grab the new 789 to CKG, there is award space but doesn't seem to want to come up with my specific connections either as a new booking or a change. I guess I'll have to pass for another day as its not worth going 6-7 hours out of my way to get the new product.