When our company flew 744's out of SYD we often where just behind the Qantas 744 with the RR engines. (we are PW-4056 at 56,750 lbs T/O thrust). We would always outclimb them, and yes we knew their pax load, which was always around the same as ours. I always felt guilty holding them down and wonder what the advantages of a better SFC is if you are disadvantaged in the race for levels. I must admit the Rollers are very nicely cowled, look good, very British, built like a concrete outhouse.