I ran the RS in my slash for 1/2 a year with a 4.5 550. It worked great however heat was a problem, with a fan max temps would be in the 110-120 range after a 12 minute heat. If the fan failed which it did from time to time temps would shoot up to 170-190 range, when I replaced the speed control I cleaned the RS and found the FET's had melted the inside bottom of the case........BB