For another data point, I just completed a flight on a United 787 from SFO to Seoul (12-13 hours) - that was a rough flight, almost as bad as my flights from SFO to Haneda (I puked on or from both flights to Haneda), and I had a wicked headache after landing.

I wonder if I have some pressure sensitivity that affects me on these long haul flights, as I haven’t felt it on domestic flights or flights from SFO to Heathrow (or back). In addition, I know I am susceptible to altitude sickness.