I was going to take it this last summer, but the lack of snow had shut the tour down for the season. I have talked with lots of folks that did take it and felt it very worthwhile, hence my desire to take the tour....maybe next year.
Here are some reviews of the trip from this year on PortReviews.com;
http://www.alaskaportreviews.com/Juneau24.htm
and
http://www.alaskaportreviews.com/Juneau28.htm
Hope that helps. Let us know how it was.
Tom