No great expertise here, just observations from our (near complete) RTW in J -

Longhaul J seats: Of those we've been in, QF Dreamtime and Skybed, CX A340 beds, BA NCW, and AA J (F) 763s, the ranking couldn't be easier.

1. QF Skybeds - comfortable, well thought out, 110v power, shoulder space.
2. CX beds - a big drop in points from the Skybeds, but better than the others. The angle and slippery surface complaints are valid.
3. BA NCW - again, a big drop from the first two. Narrow at the shoulders, too short for tall people to stretch (try the fetal position for 11 hours); opposing directions is weird and makes the window seats virtual prisons overnight, plus either I or Ms. 'Loo have had serious mechanical or condition problems with one or another (or both) of our seats 100% of the time. Too clever by far.
4. AA 763 J/F (depending on where you are) - way too narrow but great leg room.
5. QF Dreamtime (743s) - almost as bad as AA F seats on 757s or MD-80s. No, wait, that's not fair to QF. But rather disappointing given the Skybeds.

Service - CX, 'nuff said. QF 2nd, BA 3rd unless Gate Gourmet has decided to make you eat arsenic pretzels instead of lamb chops. AA 4th or better, depending on phases of the moon or something.

Meagre contribution ends.