The package that I got some with some capacitor for the motors.
I didn't use those as they are pretty big compared to those found on a yokomo motor. And anyway, the capacitors come with my Fantom TI seems better.
I didn't tried to use large capacitor (>1000uF) on the battery end and I have mixed result. I can't really remember what is the combination that gives good result. But I am testing a 10000uF to see if it is noticable on the track.
I remember I have a combination, probably an array 4700uF which it is noticable, and when I use my fluke DMM to measure the frequency to the battery, it drop to zero.
By the way, I also use the heatsink that come with it.
Where did you get the ESC and how much is it now ?