I like plastic spur gears but I have to admit, on Traxxas models they can be problematic, mostly because of 2 reasons.
Slipper is not very easy to adjust, to find a good setting where it will pull wheelies and not strip spur gear.
Second is vilenion esc, it doesn't have linear brake. When you break usually it behaves ok, but sometimes it decides to lock the motor instantaneous. I stripped multiple spur gears on Traxxas models but only when I break, not when I jump or accelerate.
At the end of this video I stripped spur gear while breaking. And i was not doing anything crazy. Obviously slipper was tighter than optimal.