Olly has one of these.
When we got it home I was really impressed with it's speed and shock setup, especially as it only cost £69.99 :
The only downside it that it has too much torque for the plastic drive shafts and CV knuckles. So an upgrade to anodised ally is probably a must.
It's likely to be more robust if you don't go full forward throttle then full rear throttle, as this twists the shafts after a while.