I'd still say get some spur gears, I've killed mine through a heavy nose landing causing the motor to slip and the gears to be out of mesh which slowly kills them over the run, a correctly mesh drive would take months to wear out even with HUGE power.
It all depends on how you drive and where, I've broken the steering arm twice but never popped a shock cup or lost a dog bone (yet)
Get them in some open space with few obstacles until they get used to controlling them, steering when the car is coming towards you is normally what catches newbys out ?. Nothing is indestructible, they are very strong though comparer to others. Drive them lick they're stolen, but you still want to get away and make it to the border! ?