Old Vader vs New Vader
In the old EU Vader would often show feelings of regret on turning to the dark side, discomfort with his suit, a diminishing of his Force Powers, and signs that their was some good left in him. The New EU Vader has no problems with the suit (Lords of the Sith describes Vader and the suit as one interconnected unit) and Vaders power to the Force has been described by the former source as strengthening and finally Filoni himself says that the good buried deep inside Vader didn't start to stir until he learned he had a child. Two different Vaders. Which one do you prefer?