For a movie that essentially a massive advert for toys aimed at 4-11 year olds, - the content is totally inappropriate for any child under 10 and some parents would think twice before letting even their 10\11 year olds watch it.
The storyline is extremely basic, with next to no character development (and for those that pay any level of attention, fequently contradicts itself). The language is crude, crass, dull and uninspiring, with dull-witted and puerile jokes. On the special effects front, Transformers is good, but the overly shaky camera movements and blurring make the action difficult to make out.
If you want to want a sci-fi\action movie with little to no storyline that features large explosions, you could do a lot better. If you want to watch a movie that will vacuously fill up a couple of hours of your life, then you should give this movie a shot.