I am 42 years young. I have been an MJ fan since circa 1970-1971. Yes, I did cry when MJ died. And, yes, I purchased my movie ticket 3 weeks in advance of the screening date.
Net review: This is a must-see, folks. Especially if you never saw him in concert, which I regret I never did. It gives you the opportunity to see MJ, the creative wizardry and the teamwork involved to put together a big-scale concert. If you are interested in dance/choreography, theatre, and/or videography, you will enjoy the show.
The dance, video and music is acceptable for viewers from about age 5 - 13. I think my 8-year-old daughter will enjoy it, so I'll take her during my second viewing!