Madara, Sasuke and team taka need development...while we're getting scraps of Madara's history, we know next to nothing about him: what does he want to do, does he give a damn about Nagato's circle of pain, does he care for his clan or is he just out for revenge, much like Sasuke?
Next up is Sasuke...for a genius, he sure missed Kakashi's words before defecting. And then he got what he wanted, he managed to kill Itachi, but instead of feeling empty and seeking a new purpose, he clings to revenge.
Team taka: they all got their reasons to follow Sasuke, but...