Hi,
We just got back, we were at Disney MGM on Tuesday.
Your 6 year old will like it alot, the 9 year old will be a little old for it. Maybe you can split up and take your 6 year old while someone else takes the 9 year old on something more exciting or "grown up".
Although, my 2 sons, ages 10 and 12 had to sit through it!! They were bored to tears, but that's because they really really felt silly being in there with Bear in the Big Blue House!!
It's a cute show, with alot of Playhouse Disney characters on the stage.
Also note, during the show, you sit ON the Floor! And, we got turned away twice because we didn't get in line soon enough. You need to be there at least 45 minutes before the show.