HPSOV: Just a little corection. It is not enough to look at the aircraft speed, and fuel burn/
pr hr. To get the most true picture use MR BENN's method. When flying from A-B the aircraft will use fuel from first "light up" to fuel cut off. So, when you are at your destination, you have to know how much fuel did we use, how many pax did we transport (including crew), how much balast such a freight/bag did we transport.
When you have theise figures, you put that up against how much "value" you got for your money; over how many miles did we use this fuel to transport all these bag/freight/pax/crew, and how long did it take.
It is not enough to compare fuelburn in cruise.