I guess I'm just old and paranoid. I'm not gung ho on buying stocks for college education. Index funds while diverse, are still subject to market risk. If the kid is 6, you've got about 10 years to build on before you want to roll it to something a little more liquid/low risk.
But I just think that you run too much of a risk of having a down slump of indexes for a several year period that eat away at appreciation. What happens if when you go to pull out funds and your account is down 20%? And continues to stay flat for a couple years?
It's not like retirement where you looking 20-40 years down the road with a payout over the course of another 10-30 years.
You have a fixed period of around 18 years with a defined payout of typically 4-5.
To me, the risk just isn't worth the reward. 6% guaranteed, or around 10%(average) with the chance that it could be down 20% when you need it?
For something like college funds, I'll stick to the set and forget nature of government bonds.