[RC-Monster Mike]

I have only stripped the big gears once (gear, actually) in a few years of brushless running. They are pretty tough and unless you are a real power freak and are particularly tough on your truck, the UE idlers will sufficiently beef up the tranny. Netman laid out the deal pretty accurately, although I would say the aluminum diff cases are a necessity (not really an option as Netman said) with brushless because the plastic diff cases flex and cause the ring gear to jump the pinion. These are the necessities, pretty much, although some might argue that aluminum bulkheads are almost a necessity too (if you have a hard time keeping the truck wheels-down, then you already upgraded these or at least replaced them!)