[BrianG]

Actually, it's all about the torque IMO. The formula is:

torque (in ft-lbs) = 1352 / kv X amps / 192

As you can see, increasing amperage and/or reducing kv increases torque. So, for a given amperage, the lower kv motor will have more torque.

FYI: you can also calculate HP without voltage and current:

Mechanical HP = torque X rpm / 5252