Trackerbee -- not sure if you ever got this answered, so...
Although we've never gone, I'll share what I've heard about Mickey's Backyard BBQ. It's a seasonal event that can get kinda crowded. It's held outside, so on a hot day, it can be kinda uncomfortable. The food gets mixed reviews -- much like the Hoop-Dee-Doo food...
I believe they have line-dancing and such that the characters participate in. I'm not sure how much interaction there is with the characters -- posts are a little inconsistent on that point with some saying it was great and others saying there wasn't much.
Many people seem to really enjoy it. If I had known about it when our kids were younger, I probably would have given it a shot. As always, a few posters have said it's not worth the price.
Hopefully others who have gone will post their specific experiences...