OT: managed care plans in DE?

Sorry for this off-topic post . . . my son with autism is eligible for Delaware state medicaid insurance coverage under one of three available managed care organizations (below), I have to choose one very soon:

Does anyone have experience (good/bad) that they would care to share regarding:
-Delaware Physicians Care
-Unison
-Diamond State Partners

I am specifically looking as to how easy it is to get referrals covered, rx coverage, etc. being as he has to see quite a few specialists for not only his autism but his other health condition (type-1 diabetes).

Feel free to email me privately at [email protected] if you have any info or experiences you'd feel comfortable sharing.

THANKS.
-BJ