High kv low gearing VS Low kv high gearing

[SpEEdyBL]

One thing that you guys are forgetting is internal resistance. Take two motors of the same design, one's 2,000 kv and the other is 4,000 kv, the 2,000 kv motor is going to have four times the resistance. So if you over tax the 2,000 kv motor by gearing for the same speed as the 4,000 kv motor, you will create four times as much heat in the windings. Of course the 2,000kv motor will draw a lot less current under acceleration, but it will also take a lot longer to get up to speed, due to the lack of torque.

A better comparsion of low kv vs. high kv would be comparing two different sized motors with the same resistance. For example, a neu 1521 vs. a neu 1512 and gearing for the same speed.