I thought it was good, but almost exclusively because of the 3d scenery and overall beauty. I'd give it a 'B'
However, the characters are very one-dimensional, the character lines were unimaginative and standard, and the plot (including the ending) was pretty much figured out within the first 10 minutes.
On a rather related note, I saw Transformers 2 about a week before. I almost turned it off b/c the writing of it was so bad. It really bothers me that action films have become all about CGI and graphical effects, and don't put the effort into premier writing or endings. Instead of trying to make a truly great action movie, the industry knows it can get away with creating as many scenes of things being blown up and still generate good revenue.