Not had an op up on this flight but I've taken this in J and F. Wouldn't pay for F again as it's an overnight flight (albeit the tasting menu was very good).

Get a backward facing upper deck seat and it's very private and quiet (and I found easy to get some sleep) - 50A was very good even though it's close to the (very large) bathrooms

Every time this year I've been through LAX there's only been 1 lounge though which gets pretty busy - there's a couple of quantas flights just after the BA one so everyone with status plus J and F pax are all crammed in there (think there is an OW F lounge opening in Jan next year but it won't help)