After watching Transformers again for the 100th time, I can honestly say that Shia's acting is among the best in that movie. Things begin to stand out, like what was the point of the Australian chick? Just another hot girl? And the black hacker guy (can't remember his name at the moment) was he just for a comic effect? Cause otherwise he was pointless, and really not very funny anyway. Also, the guy from Sector 7, with the funky underoos, he wasn't even funny the first time I saw the movie. First he tells Megan Fox that she's wearing a training bra, then he says she's a criminal and criminals are hot, while looking her up and down. FUCKING CREEPY PERV. He has a few slightly funny lines in the movie, but otherwise the character is totally overplayed and could have been left out of the movie ENTIRELY, imo.
Fortunately, Transformers isn't about the human actors, it's about the robots. That is one movie I will watch repeatedly just for the action scenes.