I loved it... The Star Tours alone is worth it...
Let the CM do the talking, even if you might the lion share of it there will always be that little thing you never thought about, overlooked, or is new... You also get to see the Cityhall little rooms with some of the extra pictures.
I would not do it with my son (6 years old) Although I am sure he would love to see the Star Tours inside and how it works, the two hour "walk and talk" would bore him (and I want him to have fun when in DLRP)
Even a 12 year old I would ask if they really are interested (teens might like to do the rides more then go on a walk, unless a Disney addict)
Other then that I would say go and do this. Even if you think you know all, there always one, two or even more little surprises...
I even think I would do this again some day. (I hope with the same luck as last time where I got the solo tour)