As soon as my Inquisitor hits 50, I plan on rerolling my Trooper as a pureblood Sith. I know that it isn't a particularly "defensible" RP choice, but I think I'll have more fun playing one -- a willingness to do wrong, inspired by a constant need to prove your loyalty to your superiors, is a bit more engaging than "I'm a perfect soldier, I follow no unethical orders."