First of all, I once read a review on ButterflyEffect2, stating the middle was pretty competent, and I agree.

The problem is that it didn't begin (or end) the way it should have. For example, it starts off too hasty, beginning at a (if not the) pivotal point in their lives. They're already 25 here. Perhaps commence the film with their HS graduation, so we can get a feel for who they are first. As far as the ending, it was on the right track, but it seems as though Nick's friend Trevor should've been his younger brother, rather than friend. This would've worked better for the ending, as far as being able to "pass the torch" to someone who was actually alive when the picture was taken.