Well, that was silly. I should have first asked what plane CA flies JFK-PEK. SeatGuru said 744 (so that's why I asked about the 744), but after tweeting with CA, I now know that they fly the 748, which looks like this:
I think that looks like a respectable F product. So, if this was your first trip to Asia and your first premium product besides UA J, would you grab this flight for the RT since availability is there now, or try to find a different way for one of the legs to try out something else/see a day in another city?