Playing travel before the big field will not make your son better. Talent is talent and hard work is hard work regardless of the league you play in especially at a young age. People that play travel at young ages thinking that it is advantages to their kids development IMO are wasting their money. Now if you are doing it because your son gets more enjoyment out of it, okay.
I don't think the facts support this. If you look, you will see that the best HS teams in your area (Mater Dei, JSerra, El Toro, etc) are stocked with kids that grew up playing travel ball. Kids that started travel ball at 13/14 seem behind the 8 ball.
Because those kids are already very talented. TB at the early ages did not make them better players. Until puberty you don't really know. There are thousands of kids that start early and don't play HS, what about them?
My contention is that getting good coaching and developing good skills early will help in the long run. Puberty will get you bigger, stronger, faster but won't suddenly make a swing better or a more skilled catcher, etc. I suppose skills can develop anywhere but I think high level travel ball is an excellent way to go to get this training.
In agreement here with Smitty. No reason to wait around until 14 and or puberty. Why not gain the skills before? TB is not the only avenue to gain the skill and development.