Originally Posted by
hearingdouble
... and just to prove that we're all different, I actively choose J on the sleeper service from Chicago over F. (In fact, I just made an Avios redemption on BA294 on a 241 from the UK, and chose J even though there was F availability and the increase in cost would have been only ~10,000 Avios per person and no difference in fees). I don't eat or drink at all on that service, and my favourite place to sleep is 62A/K - loads of room, no one bothers you, v quiet and private, and the proximity to the emergency exits means that the sleeping area is quite cool.
If you are BAEC Gold or OWE, you get a lot of the advantages of F anyway (First class check in / First Wing at LHR; first class lounge access; free seat selection; etc.). When flying from LHR T3, you can access the best OneWorld lounge in the terminal regardless of your class of travel. Without status, I think I would value F far more than I currently do.
I think on a 747 this depends on UD or non-UD J. UD-J (particularly in the window seats) is pretty much as good to sleep in as F (in some ways better). As that's pretty much all I do TATL US->UK, and as I get CCR access anyway, I don't see a lot of advantages of F. But with no UD, or where you are actually awake and eating, F is a bit better. Not hugely, but a bit.
One advantage of F not described so far: when your flight gets cancelled / connections get missed, I'm pretty sure for any given CIV/status, F pax will be rerouted with higher priority than J pax.