I will take it from friends' experience. Their hellfire pinions/crown are crap. They wear out very easy. The grub screws in the driveline falling out are a common problem resulting in no drive. The small pins in the cvd joints break easily. The plastic diff cups are weak too and can result in your inner diff gears moving apart resulting in no drive. They are so mad at that time. They found it very hard to keep their hellfire going. So this is based only on their experience, but if you guys don't have a problem encountered in hf... that's good..