While I guess it's too late to change your opinion, I would definitely choose UA on this one. Especially travelling NRT-USA, which becomes a night flight, I like being served a good dinner (UA food in F has never been bad for me, ever, although it is not up to the quality of SQ F, it is still very edible and tasty) quickly and then going to sleep for 10 hours, waking up and landing. The suites, especially in the nose of the 747 are really quiet and private with no one walking through the cabin and an aisle/window seat combined without anyone climbing over you. On the way back to Asia, however, if it were a day flight, I would be hard pressed to not choose SQ.