I did A LOT of research on this tour, and I don't think I've found a negative review yet! I decided to go ahead and book it for our upcoming trip in April; unfortunately, due to bad planning on my part, we will be at MK on a "BAD" day, per the Unofficial Guide. Since we'll have already visited MK several times previously on this same trip, I decided to go ahead and book this tour, as it will allow us to:
1. do something different, as we WILL have been to MK several times already
2. focus on the tour and NOT on the crowds of people around us, and
3. give us front of the line access to at least one attraction - probably Philharmagic, from what I've been reading.
I've posted 2 links here that will not only give you some general information on the tour, but also several people's personal reviews of the tour. The second link is a link to a thread here on the DIS boards, where a lot of people gave their 'thumbs-up' of the tour!
I hope this information helps!
Family Magic Tour
FMT Discussion