As I undoubtedly learned here at DFP, I'm a big fan of this system. Certainly at the younger ages.
So many problems occur with a 10U team with 12 girls on it. Parents griping about playing time, girls don't get enough reps/at bats in games, parents griping about playing time, parents griping about playing time and parents griping about playing time.
At the younger ages, girls simply don't miss games. Fewer injuries, fewer conflicts, etc. I love having a lean team.
Regardless of age, if you've got more than 11-12 on game day, playing time starts to become a problem.
Unless you're that team that everyone wants to be on no matter what, the capable players who aren't getting enough work will eventually leave for a team that will play them more.