The 767 is slow and so is the 330 at .82 I understand the 330 comes back to .78 in turbulence. The 744 can give you .85 in turbulence and 310 kts on descent. If you ask nicely I have no problem with .87 and 350 kts on descent in a 744. Why not drop a faster aircraft in an early descent underneath slower traffic ahead? I know it's rude to push in etc but some of the vectors/speed restrictions to sit behind a 330 are agony at times. Why not use the speedy ones to advantage. The North Atlantic is filling up with slow traffic these days and it seems to cause more flow problems than the faster ones. I must admit I'd rather have a 330 if I was paying for the fuel.