I've never been in Best Buddies, but the chapter at my school isn't giving me a lot of positive vibes.
I've had the advisor of BB as a teacher before. I thought she was rather difficult to communicate with.
There are a few students that I know for sure are in BB. The way they talk to me, I think is what some people would describe as "patronising" or "talking as if to a little kid". Done with good intention, and they may not even realise they are doing it, but I still notice. (I've never told them I have ASD/whatever, but I guess I'm worse at masking it than I thought.) I didn't realise this until fairly recently, though. Makes I wonder about their buddies, if they get talked to similarly, if they notice, and if they care.
But that's just my school. Don't know about other schools.
Are you planning to join as the student with or without a disability?
_________________
Life ... that's what leaves the mess. Mad people everywhere.