As I understand it, the eGo Twist was one of their earlier models that supported variable voltage and a battery shut-off (at the time, the eGo-C
batteries did not). Now though,
joyetech sells an eGo-C Upgrade battery that also offers variable voltage and battery shut-off. So I imagine the differences between an eGo Twist and an eGo-C upgrade are little, if any. A standard eGo-C however will not have these features, as I understand it.
I also believe the eGo-C
batteries can take either A or B type atomizers. Not sure about the eGo Twist.
I've never used a Twist, so I can't speak to which is better, but I have an eGo-C Upgrade 1000mAh passthrough battery with an eGo-CC Clearomizer, and I absolutely love it.