I'm looking for an answer to this too. My son is 14, pretty big, hits the ball hard and really likes the Demarini Vexxum; which has a lot of flex. He's used several different Demarini Voodoos but never hit well with them.
I don't know enough about bats to give good advice. My kid likes the Vexxum, hits well with it and it's cheaper than a lot of other bats.
So, unless a convincing argument is made for some other bat, I guess my son will continue to use what he's most comfortable with.
I wish I knew more about other brands, any advice or recommendations are greatly appreciated.