I spent another hour playing with my two MMX ESCs. Both still make the Tekin ROC412 cog like a mofo. Yet the 35A HobbyKing ESC is still as smooth as butter.

I'm giving Castle a chance to respond to my latest email, but I've already started the process of returning one to Tower where I bought it. I'm looking to replace it with a Tekin RX8 or HobbyWing. I've had tons of luck with HobbyWing so I really like them.