how do you evaluate a director's work?

As someone attempting to juggle directing three seperate productions at the moment, I feel like it has ruined me. I used to enjoy the story, now when I see a play I'm analysing the direction! My friend often quotes Andrew Hale, who told him that in any production the Director is 'ultimately responsible.' If it all falls to pieces, it's the Directors fault, no one learns their lines? The audience is bored? Bad reviews? Poor acting? Lackluster set? At the end of the day the Director has to pull it all together, or let it all fall apart. Cara Sutcliffe, one of the first Directors I ever worked with, used to say that the job of a Director is to take the actor to the next level. Look at where they want to go in the long term and where the actor is now, then get them that next little step. I've discovered this to be a frustrating and often painfully slow process since I've been on the audience side of the stage. I've worked with other directors who get the actors to good enough, then give up, never pushing us to our full potential...then I've worked with directors like Cara who have brought something from the actors that even they didn't know was lurking inside of them, one painful step at a time. A daunting task. Everything is your fault if it all goes wrong, everyone forgets about you if it all goes right. Well except maybe the other directors, who are busy thinking, 'Now why did they do that?' (Very interesting forum topic by the way)