I enjoyed it, but I didn't think it was as good as the first one. Granted, some people will jump all over this comment because it's a Bay film, but say what you will, there was more character exploration in the first one, which I liked, in this one, it was like, ok, you know everyone, let's just throw them in action now. I know Bay films aren't character films, but I think TF1 was more a character film than TF2 and I'd have enjoyed it much more if the sequel had been on par with the first in that regard. Fights were much cooler this time around though, and I was very excited to see Optimus take center stage, he'll always be my favorite and I wasn't a fan of how much attention Bee got in the first.
The only other dissappointment for me was the lack of non-robot action with the autobots. One of my favorite scenes in TF1 was the chase between Bee and Barricade, but this time around they didn't have any cool scenes with them in vehicle mode.
Last negative comment, not a fan of the autobot/human heaven thing, I think that gets a little hairy and should have been left out or written differently.