There are plenty of kids in the older area, too. Just depends on which streets you choose since some are better than others.
Both are exceptionally good neighborhoods, and I can’t think of any “cons” where either is concerned. It really all depends on whether or not “new” is more important to you, or if you prefer an older neighborhood with no HOAs or Mello-Roos and older, smaller homes (often with larger yards and more privacy).
People tend to have strong preferences one way or the other. Do you have a preference for newer/larger homes on (generally) smaller lots with HOAs and MRs, or do you prefer older, smaller homes without the extra fees (but you might get the very rare neighbor who lets the grass die and has a driveway full of cars)?