I can't say enough about WDW and autism acceptance. Our first trip was as if we had finally found home: no need to explain non-typical behavior, CMs so understanding of meltdowns, just perfect.
Another benefit is how kids (well, mine, although I've read of others who responded in the same way) with autism come out of their shell at WDW. I could go on and on, but suffice it to say, our first trip was supposed to be our only trip; after DH and I saw how much our son prospered at WDW, we bought DVC (and added on three months later).