There was more adult-oriented dialogue and themes in the 2nd one, I can assure you.
Lots of shits and asses and damns. The only cheesy dialogue parts are when one of the characters says the letter "F" in place of "fuck." It would have been better if they made it to where he stalls himself from saying the actual word, rather than the first letter of it. The two "ghetto" twin autobots had some edgy dialogue, with the use of pussy and the n-word (I'm pretty sure I heard it a couple of times from them). But overall it wasn't as "pg-safe" as you mentioned about the first one. And yes, there's still the teen love sub-plot crap going on, but I guess they just have to have it for whatever reason. It's a lot more mushy and dramatic in the new movie too, so that's probably an even bigger put-off for you.
I guess we should all just agree on the fact that these three aspects are the only things worthwhile in the movie:
Amazing CG work
Great action scenes
Megan Fox
PS: Shia LaBeouf? I don't hate him but I think he's just another one of those young "rising actors." He's not really that bad at what he does, and he seems unique compared to the usual young actors out there. His usual character personality is different from pretty much anything I've seen, but do note I don't watch a crap load of movies and I'm not really very knowledgeable about famous actors.