My 10-year-old daughter and I took the tour in August and we didn't see any characters backstage. The tour seemed pretty regimented as to what it contained. What I mean by that is we went from one scheduled presentation (for lack of a better word) to another. And going to the employee dressing room wasn't on the agenda.
In general, though, my daughter loved the tour and loved the fact that so many children of all ages were there with her. We even had a few teenagers who took it upon themselves to help corral the younger ones during the "troop movements." The pace is fast, though, with early mornings and a couple of late nights if you take advantage of all that is offered. You might want to consider your kids' stamina levels when booking the tour.