I finished 3rd at the Region 2 Asphalt touring race with my Mamba Max running in brushed mode. I have ran stock and 19t without having any problems. Those type motors don't even get close to pushing the capabilities of a Mamba Max. I ran the high powered brushed setup on mine for months before I ever ran a brushless motor before.
Plus with the new deadband setting you can make the brushed setup even better and smoother than ever before. I ran mine before this newest update and it was still excellent but a little less deadband would of made it even better (now you can do that.)