Maul vs sith assassin who is better?

I currently run maul on my nihilus led sith team due to his double damage to jedi. However I am debating if I should use assassin instead due to her various buff gains on her basic and her overall move set. Also does maul lose all of his health boost benefits from his unique with nihilus lead? You'd think that with all the potential health boosts he should get it would be more noticeable but apparently not.