I saw it yesterday.
The best way to experience the movie is to see the original first and turn off your brain, but even at that it's still a dopey under-plotted effects-driven disaster (though well done the effects are.)
It's pretty much a sequel made for fanboys of the first film's action sequences and for people who love to waste their time jacking to Megan Fox's body.
I also don't know why it was so long. In fact, it's six minutes longer than the original! (Eight for the IMAX version)