My parents recently flew NH 6 NRT-LAX in New Club ANA. They said it was spectacular, better than SQ Raffles in almost all respects. I'll try and post a more detailed report soon, but don't think there's much question that NH is the way to go if you can get it. SQ 11/12 also ply LAX-NRT and also a good option.

Frankly not worth using miles on UA when the others are available and the irony is, you're much more likely to get either of those carriers (particularly in C or F) than UA.