after watching 60ish episodes of the original series in order, I can see where Turtles Forever got their kicks on the old ones. They were more remembering the turtles...essence, rather than their actual characters. I guess it didn't have enough time or care to establish their personalities, they gave priority to the story which is fine. I just enjoyed seeing April and Irma in that walk by, or original Rocksteady and Bebop pre-mutation.
haven't seen 2K3, but I saw Turtles Forever. It's kinda cute how they're annoyed by what made them popular. then they all get shown up by the comic badasses