Prepaid Tuition vs. 529 State Sponsored Plans

My wife and I are using the Prepaid Tutition for our child (12), which locks in the tuition at a certain rate and we pay monthly in order to hit that mark. Now, I have 2 other small children (1 & 2) that we're starting to think about college for and I wanted to get your opinions and factual differences between the 2 plans. We are evaluating on using one or the other to fund the other 2 children, just not sure what option is better.