Just dealing with facts, based on ISA conditions, FAR takeoff requirements and the highest thrust available for each engine type, the required runway length requirements are:
-300 (63,270 kgs) = 7200 ft.
-400 (68,040 kgs) = 8300 ft.
-500 (60,550 kgs) = 8100 ft.
-700 (70,080 kgs) = 5200 ft.
-800 (79,016 kgs) = 6800 ft.
-900 (79,016 kgs) = 7300 ft.
Guess that its fair to say that the NG is the better performer
Please remember that we live in a world of derated thrust, we are planning to use ALL or at least most of the runway!
Mutt.