From the amazingly titled On Being a Happy, Health, and Ethical Member of an Unhappy, Unhealthy, and Unethical Profession (a):
By being a smart consumer, you have a chance of distinguishing the good big firms from the bad big firms. Do not expect too much, though.
As I have explained at length, big firms just are not set up to give their lawyers a chance to live full lives.
The only people who can make big firm money without working big firm hours are the most senior partners who are living off the skim. In the end, big firm life comes down to spending eight years or so being exploited a lot so that you can spend another eight years or so being exploited a little so that you can spend another eight years or so not being exploited so that you can finish your career exploiting others.