You can't compare the two. Plastic internal gears in a Magnum gearbox, on anything more that Titan power, will be roasted within the first few packs. I break steel gears, all the time. As to "put a little oil in there," that's not really the problem. I have 11 vehicles based around the Magnum gearbox, including those made by Venom, FLM, RPM, as well as black and grey TRX boxes. The RPM is the loudest one, hands down.
There are no atheists in the foxholes / There is no intellect in the air / There are no scientists on the way down / Just a working example of faith versus physics. --El-P, Flyentology