I wasn't sure I'd want this sequel. The 3rd movie nearly did me in for the entire series, but pirates, man. They get me every time. I blame it on growing up and riding the ride at Disney back in the day.
I digress. I wouldn't say this movie was without its flaws, but I think it's a good starting point for a divergence of Jack--which is actually what I had originally WANTED with the actual sequel (#2, that is). We learn a lot about Jack in this movie. We learn a lot about the people around Jack as well. And we kind of get a sense for how he turned out to be like he is. Not everything, of course--Jack remains, still, quite the complicated fellow--but a lot.
And the rest of the characters, old (like Barbossa) and new (like our lovely love interest), are fantastic. My only complaint about the series is that they still enjoy telling without showing, and they rarely like telling you the whole back story.
But Jack still remains my favorite pirate, and that is, quite frankly, that. I'm actually looking forward to the next.