It looked amazing but was frankly a bit of a mess. It was far too long, and yet the pace was relentless, it was like the longest roller-coaster ever, it really needed to slow down once in a while. The plot was lost amid all the action, the script was some after-thought, and the new characters given no chance to establish themselves. Example: in the first set-piece Sideways is shown as a kick-ass slick autobot warrior, but where is he after that? What was the point of Sam's geeky college room-mate? Lots of new robots but no real point to their inclusion other than to satiate the fans desire to see more than the handful in the first film.
I dunno, I guess punters just wanna see CGI robots kicking the hell out of each other, and it had that in spades, but even then some things bothered me. Megatron seems a lot weaker compared to the first film, and Prime a lot stronger. Also, the action was nearly always from the subjective point of view, as if you were standing right there in the middle of the fight, making it difficult to tell what was happening.
And why were all the decepticons grey? Why were the pyramids suddenly in Jordan? As for the twins - just WHY??? Surely these were Michael Bay's equivalent of George Lucas' Jar Jar Binks. Pointless, childish nonsense based on dodgy stereotypes.
And what is Michael Bay's obsession with the military? At times this seemed more like a film about Desert Storm or something, there were so many shots of tanks and troops deploying, planes taking off, control room scenes, and air strikes 'bringing the rain'.
That said, it's transformers, Prime is a legend, and the main human characters just about managed to keep it all together. Shia was dependably good, and Megan Fox....well, she excelled at what she was required to do