RE: 3DX, wanting to go brushless out runner
Slow response can be a heavy prop, too much pitch, or poor speed control setup. Some speedos have a soft startup setting to save gears. Obviously this is unnecessary on an outrunner. Actually I dont use soft start at all even with gear boxes since i feel this gives better throttle response.
AXI's are diffrent. they are longer and smaller in diameter. I am not familar with PJS motor but im willing to bet that based on the design the AXI's will have better response.