@Stephanie-Hider Attending guests do review your work--if you pay for a portfolio review or manuscript critique. And then it is first come/first serve in who reviews your work (anywhere from art director to fellow illustrator). Some chapter's conferences allow anyone to put their portfolio out for all to peruse and the visiting lecturers will almost always look at them. (That is how my friend's agent found an illustrator for one of her books.) Another way the conferences help is if they have intensives. The intensives have smaller enrollment sizes so the teacher can work with you on a more personal level. I've had some great "free" critiques from attending those.
@amberwingart Though you can't join now, if illustrating in children's books is your dream, it would be worth saving up for. You aren't limited to your chapter. I often attend conferences in nearby states. And I know people from all over come to my chapter's conferences. Plus, it is a great community --much like SVS. And while I totally agree with Lee White's assessment, I have some good friends who are very accomplished authors who are still part of SCBWI because it is an easy way to get even more contacts...something that never ends, even if you are accomplished. That, and conferences are like a huge reunion for them.