Originally Posted by bjspinner

We run the Hobbtwing 13T brushless system, it has plenty of torque.

Heaps of wheel spin equates to tire wear. With control tire's that weight slows down the spool up speed (less wheel spin more tire life) and also carries speed through the corner (smoother cornering).
I have tried them all (diff's) the oil filled gear diff is by far the best that I have used.
I don't care to much about the weight, my MO5 tips the scale's at 1500+ grams and it is fast.