The Xerun 2000kv motor is definitely the smoothest sensorless motor I have raced so far and also the coolest running! I'm sure the sensored motors are a little smother at the very bottom end of their rpm range, but I try my best to not go that slow
Also the one Tekin motor I tried (1900kv) geared for the same mph consistently ran 40 to 50 deg. warmer!