A lot of decent discussion here. cashmom, you really are getting the nutshell of the atv debates as far as size/power/longevity concerns. I have a TRX 90 for my kids as well. Great little quad for a new rider your sons age. Buy used as they can really take abuse and be ready for more. You can pick one up easily 1/2 to 1/3 price of new with plenty of life in it. Yamaha has recently released the 125 Raptor, same chassis as the 250, but smaller tires and motor. This would be a good step up after he gets a year or so of ride time under his belt and masters the basics. Might be OK even now, but it does have a manual clutch which is more difficult to master and may get him into trouble initially. Stay away from the Chinese stuff if you are looking for a low maintenance, just put gas in/check oil and ride machine.