We have taken our kids in 2003 (5, 4 & 2) and 2006 (8, 7, 5 & 2) and the 2 year olds were not thrilled (both fell asleep) but the older kids enjoyed most of it-because it is familiar to them. I think it may depend on if your children are
a)Familiar with the Christmas story/songs
b)Comfortable sitting for stage performances that don't include characters or kid friendly, attention grabbing effects.
I'm not sure how to be PC about this, but it could be compared to a Church service, so if they don't have trouble sitting through Church, they should be OK. Wether or not they actually enjoy it...I can remember how I felt sitting through Church as a kid.
DH and I absolutely love it though!