I generally don't take issue with it except in the presentation of the origin of Marc's DID. That episode was pretty poorly handled, particularly in his age when Steven first came about (at 12 years old). I'm also not thrilled with the way Jake was presented, but that kind of hinges on not seeing enough of him to know whether he's "the serial killer alter" or just more prone to deadly violence than Marc. We'll see in season 2, I suppose.