I think, I'm not the only one, who is tired of paying or feeding a follower, and thinking they get plenty, but suddenly they start running away at say 50/133 HP. (companion)
It's really annoying, how we don't have a more accurate measuring tool other than their dialogue, which is extremely vague to be honest.
Perhaps a points description, where, in the dialogue, you ask a question about how they feel about you, and they'll say loyalty at the end of some dialogue such as:
"I think you cool and all but with everyone trying to murder you... I don't know." (Loyalty: 62/100)