My son just finished 12 years with the twelve and will start college baseball next month. It's convenient when they are young and living here. HS ball is all of the teams mixed up (CS, Katy, THe Woodlands, San Antonio, etc). He enjoyed his time, but the organization is big. It just depends on what your goals are. My son loved meeting kids from all over, while some of his friends missed not being all together (the CS teams tend to remain with the same set of kids through 14u).
If you are looking for a smaller organization for HS baseball I'd also look at Hunter Pence. They also have youth teams.