The threeholer. B727-100 with -7Žs that is. YouŽll get about 1500 to 2000 ft/min wether you climb @ 250 KIAS or 350 KIAS.This works up to the 20Žs depending on weight and temperatures.
Once you point your nose to your destination youŽll get there a lot quicker at the higher speed. Overall trip fuel consumption is actually a little lower due to the saved time.