The original was a sort of surprise -- one expected a movie based on a toy franchise to suck, but it was actually OK. It had a bit of wit, probably Spielberg's influence. The new movie is not nearly as good. I give it about 2.5 stars, with that being an average of 1.5 stars when Megan Fox is off the screen and 5 stars when she is on the screen. The director avoids doing anything to advance the plot when she is on the screen, which is good because it is hard to concentrate during those moments.
The one highlight for me was that most of the college scenes were filmed at my old alma mater Princeton. With all due appologies to my friends, there is a certain amount of cognitive dissonance to seeing 40 or 50 consistently smoking hot college girls wandering around the Princeton campus. We had a name for women like that when I was there -- we called them "visitors."
One bit of credit -- unlike a lot action movie sequels, the plot was mostly coherant. The humor was strained, more sophomoric and less witty than the original. Thedogs having sex in the beginning was gratuitous, for example.
Anyway, my kids enjoyed it, and it was a decent way to spend a summer afternoon when it was 107 outside. Air conditioning always adds at least 1 star to every movie during a Phoenix summer.