Flying CAN-WUH-SVO, same flight number, just a short stop in WUH on A332. There are both Business and First cabins. Im booked in paid Business, which means I can upgrade to First for 20000 Sky Pearl miles (I can open an account and transfer from SPG).

Reading reports on CZ First and Business, its not clear how much better their First is compared to Business. I have heard rather unappealing reviews of CZ and want to minimize the unpleasantness, would First be considerably better on this flight or should I just stick with J and hope for the best?

I understand the ground services are the same for Business and First, not sure about wine choices between classes, or food options. Seats are flat in both Business in First but obviously First is more private.

Thank you for your opinions