I should point out that though I have high hopes and great expectations for RDI, we're not keeping all of our ASD eggs in the RDI basket. The other interventions we are continuing are:
Vitamin supplementation with Super Nu-Thera
Occupational Therapy for Sensory Integration Dysfunction
Wilbarger brushing protocol
Sensory diet and visual schedules at school (and sometimes at home)
Adderall for attention deficit (still in trial phase, though with positive results)
Our own "ABA-style" (in quotes because actual practioners of ABA would probably shudder at this assertion; it's much more a flying-by-the-seat-of-our-pants sort of thing) reward systems (sticker charts and earned chips) to target very particular goals like using the toilet, writing his name, and going to sleep by himself
And a whole lotta love.