F is definitely better than J at the moment which is suffering from an awful degradation of the soft product bar BA's bedding itself which is still good (though they've cut out the "day blanket" from within the CW bedding set).
But IMO, avoid BA altogether. Fly AA, IB, AY or even EI - all of which are giving a much better onboard experience at the moment from a soft product perspective. Yes they're not direct, but you do stand to earn more Avios/TPs in the process than flying direct. BA is just really really taking the biscuit/p*ss at the moment from an onboard customer experience perspective on long-haul services. If you really want, you can book it with an BA codeshare. The only good things BA are doing at the moment is Club Europe and their LHR lounges.