DL says it is 7 inches more recline that coach.
I found PS to be a little less recline than domestic F and less than the Premium Economy cabin in VS. Same pitch as VS but narrower seat that VS (18.5" vs 21"). PS in the refurbished 777 is 19" wide.

Still, I preferred to spend more money on a nicer hotel in PEK than on D1 for the flight, and I don't regret buying PS one bit. When I bought PS, DL was booking the connecting domestic legs in F. They stopped that perk back in July and now book the domestic connections in C+.

I arrived refreshed due to the air quality and pressure more than due to the deep sleep I got en route.