The problem is that they are the main protegonists as they are all ment to be played that way. It's like starting a game with the Baalspawn, Ciri, the Greywarden and pick-your-superhero. The idea sounds nice at first - basically full fleshed origin stories - it worked for DOS, right? Except it doesn't work so well with D&D rules (because of classes). And it just gets a completely strange feeling when you put them all into the same party. And it gets far worse when you are a custom character that doesn't care about the tadpole, which turns you to the strange kid at the party that nobody cares about (and they will tell you that).
But it could be just me. I also never liked the comics where superheroes where thrown together... they might be cool on their own, but combined its kinda South Park playing ninja's, just there are 5 Cartmans playing with a new kid (pure hyperbole here from my side).
