Bah, I think I'll wait for the DVD so I can fast-forward to the good bits (Robots and Megan). 2.5 hours is ridiculous, I mean who really cares about the feeble plot, all we want is robots kicking hell out each other for a while.
It's much the same with Terminator Salvation: effects good, plot feeble.
Incidentally, to reinforce that the plot/script is for kids in Trans1, there is a line where the big all-american robot (prime-thingy?) says something like "We lived with the Decepticons but they betrayed us". Always makes me laugh as, DUH!, with a name like decepticons what exactly did you expect you robotic twonk