I dont gamble with them. Vader's CE is only used situationally. I just prefer to have a beat and Vader Cots is quite good at it. Also, I dont need more than 2 SCs as basing them is a very bad idea. Its all about careful positioning and counting, both of which are my strengths
And I am certainly not going to reroll when I need a 6. Other than a game end needed kill, perhaps that is. Otherwise, the CE is just a situational bonus. Now that may sound like I should drop Vader, but that is not the case. I do use the CE. I just use it carefully and when needed. Plus Vader himself is a pain to kill, can control gambit, and has some great force abilities when needed.