Truly prefer LX
First the C comparison. Within the last year I have flown long haul C on CX (both the coffin seats and new C), JAL (the new Sky Suite SS7), SQ (the wide C), LX. And for years all the versions except the newest one on AF.
Taking account of all factors: service, food, wine, IFE and seat, I prefer LX. Here is why. First the most important factor, the seat (after all sleeping and comfort is most important on a long haul). I like the personal space on LX on all C seats except the paired A/C seats in the odd numbered rows. Of course the seat is fully flat and offers an excellent sleeping space. The credenza is fantastic. I can set up my ipad and watch it if I wish (could not do that at all on JAL, AF, or CX.
JAL does offer a good sleeping space, but it is a struggle to convince the flight crews to lower the cabin temperature below tropical settings. 26 degrees on one flight! UGH. But the JAL seat has a small eating tray and no room on either side for an iPad.
I find the CX seats to be too confining and hard to exit or enter.
AF is simply lame. Awful. Angled flat with someone right next to you.
Food: Again nod to LX. CX food has gone way downhill. Pathetic actually. JAL serves awful wines (but very good champagne....go figure). SQ food slightly better than CX, but still behind LX. AF food is very close to LX. LX main courses are better; AF desserts are better. Wines are a tie.
IFE. Here is where LX falls behind. CX, SQ, JAL all have far superior screens. On the other hand JAL has the worst choice of films I have ever experienced. UGH. Too bad because the screen is great. CX and SQ have both great screens and great choice. AF is about equal to LX.
Service. Frankly I think LX service is better than the famous Asian carriers. The Asian flight attendants are all smiles but not very efficient at what they do. LX is just as welcoming but extremely responsive and efficient. AF is highly variable. You can ring the call button for a decade and no one will come.
So taking the sum of all the parts, I think LX is doing a good job. Replace the IFE screens and it wins on all the parts in addition to the sum.
Your mileage may vary.