I was surprised this thread did not exist yet. I saw this film today, and it was a LOT of fun. It's pretty long for this type of movie, but the action keeps it going along at a good pace, I felt. I think my viewing experience suffered a bit, actually, because the place was so full, my brother and I had to sit in the front row. There was so much action on the screen, it was impossible to take it all in that close to the screen.
There are some mature references which give it its PG-13 as much as any violence, most likely. You may wind up explaining something to your youngest ones before you planned. Depends on each family, of course.
And, yes, it definitely bears all the marks of being a Michael Bay film, but loads better than ARMAGEDDON. There's a funny reference to that effect in the film itself!
Sean
bkwormonthenet