The redcat system is NOT sensored. It's sensorless and I think the motor could be a bit better and the esc isn't all that great. It coggs quite a bit and with only the 3300kv motor.

And I've never heard that the mamba motors use 380 sized rotors. I've heard that on the ez-runs, the 9t, 13t, 19t, etc, etc use 380 size rotors and that the 13.5, 8.5, 17.5's use the regular 540 size rotors