I don't know about brushed motor use, but I really like my SpeedPassion GT. I am using their 13.5 also and think it is the fastest of the bunch. I don't ever seem to have more speed than everyone else, but just a whole lot more rip out of the corners. The speedo and their motors also seem to run very cool and I don't think there will be any problems with them in the outdoor heat.
-Brian