HV-Maxx 4.5 or MM and 9xl?

[RobK]

I can tell you from personal experience from having purchased the original HV4400 that it was difficult to keep cool in my modest Revo. Once I upgraded the rotor it was like a different motor--more powerful (modest amount), but it ran a ton cooler. I usually run this for about 40 minutes (8AH lipos) without it getting too warm on a tight track. Also, the KV numbers are misleading, because I had to gear down when I upgraded the rotor.