I have been looking at 837 from SFO-NRT daily and it seems to have escaped the worst of the 747 problems. Seems to be arriving consistently within 1 hour of on-time which means all reasonable connections in NRT are fine. Have not seen a cancellation in a long time. Might this flight be given priority since it is probably a high revenue flight and also has the good fortune to be the first 747 departure of the day from SFO (meaning it can steal another 747 if the scheduled 747 has an issue)?