I've seen this question a lot, and I don't really understand it. Age of Worms is 12 adventures strung together, and as you can imagine, you pretty much do it all over the course of 12 adventures.
Arguably, the most effective character in my Age of Worms campaign was the ranger with Favored Enemy (Undead). Wouldn't hurt to have someone like that around to dish out a hefty sum of damage.
That was certainly an issue with my first character, and a big part of the reason I retired him in favor of one that I could enjoy more. I had in my mind that I'd play the character a certain way, and my backstory was part of it.3. DM Dependent: The AP does not have a lot of room for character backstories as written. The DM will have to work to insert these in. If I was going to run it, I would ask for backstory light characters.
That was certainly an issue with my first character, and a big part of the reason I retired him in favor of one that I could enjoy more. I had in my mind that I'd play the character a certain way, and my backstory was part of it.
My backstory was promptly forgotten/ignored and my character was driven by events in game along a different path than I intended for him to go. I'd say that that bit of advice is probably pretty good with any but exceptional DMs who specifically make a point of integrating character backstory into prewritten modules.
Not something that I'd think is common.
Also, I think Age of Worms is probably the most iconic DnD campaign I've ever been involved with. If you are looking for the "DnD Experience," I can't recommend this AP enough.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.