Affliction has leas burst but better for consistent damage- healers can't dispel your ua or they'll get a silence + hurt. You'll have better control for 3s. Destro is downright insane burst when timed right with a lot of utility, but easily avoidable if they have a good healer. Both have to be played with a healer, pref a disc or rsham. Im prob off a bit because i dont play a lock usuallu but that is what i can get out of watchin 70 ones.