I stopped running all three of my MTX4 after it stripped 7 gears in one day. I even had a mugen driver helping me to set the gear up. The problem is that there is about 1 mm gap btwn the clutch bell and the 2nd gear housing, if there is some excess chassis flex, the clutch bell will contact the 2nd gear housing and strip the 2nd platic gear.

Now I have tons of mtx3 to last me till the MTX5 comes out. The MTX3 is like a tank. A little slower but I don't run the risk of blowing out 2nd gear.