[suicideneil]

The new emaxx diffs will last a while- how long depends on how much abuse they get- lots of stopping & starting will strip the teeth sooner rather than later- the UE or other 1/8 diffs will outlast the truck usually..

The hvmaxx pro systems just come with different kv motors- 4.5 is fastest, 7.5 is slowest. That also means the 4.5 will run hottest and be most sensitive to gearing,- most people opt for the 6.5 for general bashing, its a nice mid-range motor for speed and power, easily accepts gearing for 20mph upto about 35mph, in a stock weight emaxx ( 10lb-ish ). I think that would be a good choice for the kids to use really, they'd have a hard time killing it unless they drive it into a lake or something..