Having recently flown JL F LAX-NRT and later HND-LHR, here are my observations:

The seat and bed are super comfortable. The middle seats are considerably hotter than the windows. No problem if you wear the PJ pants and a regular t shirt though.

The FAs were very friendly and engaging. When I mentioned that I liked the cedar chopsticks they gave me two sets as a gift. They made conversation about travels etc.

I got to keep my PJs but my GF had hers confiscated ex-LAX (she didn't tell me until after the flight, otherwise I'd have asked for them back as I'm not sure that they reuse them).

The HND lounge is spectacular. Probably my favourite in the world right now. For me, it beats the likes of DOH, VS clubhouse LHR, TG BKK, The Private Room and The Wing. Riedel glassware, runway views, massages, live chef station, John Lobb shoeshine service. The list goes on...

Ex LAX things are worse. The QF lounge was nice enough but no runway views or notable food and drink items. No ground services etc. I actually prefer the QF J lounge in HKG, although having beenin the AA "flagship lounge" in JFK I do get that this lounge outperfroms vs its US peers

The catering was significantly worse ex-LAX too. In some cases I had exact replicas ex-HND and the difference freshness and attention to detail was significant.

The amenity kits are awesome (ex-LAX this is thew one thing that I preferred). Loewe is a seriously good brand and the additional Shiseido kit was a great bonus.

The PJ's are also super high quality and I've worn the pants for lounging around the house since coming home (don't get them confiscated!)


Comparisons to CX F:

I think I prefer the CX seat. Obviously more private wth 6 vs 8 people. The service on both airlines is equally good.

I prefer JL HND lounge to The Wing.

F&B is better on JL

Aesop toiletries are my favourite ever but the Loewe kits are amazing... so a draw.