Just want to note that in many areas, the kids who play 18U are the ones who are not going to play in college, more of just a last summer of ball. So it's not necessarily the case that it will be better baseball.
On the other hand, some baseball is better than none. OP said in a different thread that he would have to play 18U, so I don't want him to think that it's necessarily a bad idea. It will have pluses and minuses, for sure.