Can I just say, I've found Vader to be my new go to commander. His effects on red dice alone are worth it early in the game when you have plenty of defence tokens.
I'd say he easily improves your average damage output by 50%. (I'm sure the maths doesn't quite back that up but it sure is my experience).
But even more so, I'm pretty sure I lost around 4 ships over last sundays tourney through excessive rage induced damage boosting via the dark side. I definitely spent too many tokens vadering.
And I think that's absolutely great. They nailed his card.