My 880kv power up 450 slow fly has less power, but much more torque and thrust at lower rpm's. When you hit full throttle, no real differance between half and full throttle.
My 1100kv power up sport actually takes less amprage untill about 3/4 throttle, but has less torque and thrust at lower rpm's.
They both hit within about 10 watts of each other (230 for the sport and 240 for the slow fly), but because I do most flying at 1/2 or less, the sport motor is just as, if not more efficient and hits about the same flight times if I horse it around, and longer if I don't. It also spins a 10X5 where the slow fly throws a 11X8.5 for peak performance.
On a "sleek" or symetrical wing though, I think it would be the other way around. I am amazed at how big of a differance you can make just with a prop change and watt meter. If I flew my slow fly motor with a smaller 10X5 or 10X7 it might last longer and pull less amps, but it would have less thrust. You need to find a good ballance between thrust and amprage. I like to have a lot more thrust then I need to fly so I can knife edge, hang off the prop and have plenty of extra power to get out of trouble.