I don't know, I'm boycotting JL except for a couple of flights that I know are good ... it is a sleazy way to do business to have a "bait and switch" F product. At least on some routes, such as NRT-HNL, there is fair warning that it is a different product (flight operated by Jalways instead of JL; a bit like QF and Jetstar). I suspect that the current set of premium routes is LHR-NRT, JFK-NRT and ORD-NRT but I don't know if there are others. JL is not helpful in answering this question (rather, reservations thinks there is no difference between the various F services). I'm not exaggerating in stating that the worst JL F service is almost like CX J, so there is quite a difference.