starscream, I find the car doesn't coast freely when the throttle is released suddenly. Looks like it brakes for a split second and then lets go again. I'm guessing it is specific to my motor and this firmware as I have a Jazz 40-6-18 and Hacker C40 in another car and it runs great.
I'm going to be putting a Crowdpleazer body on this car, so it will eventually be run without much ventilation (no fuel cap and engine openings). With the stock body installed the ESC gets slightly warm - maybe 35 celcius? The motor gets hotter, but cold enough to keep two fingers on it - I would guess about 50 celcius. Will try take more accurate measurements soon.
There are still other things I still need to do. Most important is sealing the motor. I'd like to run it on the track sometime against some nitros. :)
These Jazz ESCs are actually well priced IMHO. If you look at what the alternatives cost (MGM, Schulze, etc.), they're dirt cheap. I wish they were more popular in cars - that might give Kontronik reason to extend their car firmware support. Personally I'd like some improvements made to the forward/reverse program.
It seems that the more voltage you add the more power the braking has. Try and set your EPA to see if that helps. The first video I made you can actually see how strong the brake is: http://www.youtube.com/watch?v=-yrzb2EYsug. I adjusted my EPA and it was working really good.