This is a question that has no answer, simply because different people want different things out of their work and for their life.
What size firm are we talking about? In what field? Large firm litigators work 60+ hours a week. A large firm tax attorney may not work as many. Firm life is also a question. Some would die to make partner in a large firm, and will do whatevet they have to for the huge paycheck. Others resent the long hours and conformity and would die before setting foot in a large firm. Also, your experiences at a small firm will be very different than a large one, so this isn't even representative of the majority of firms.
Working for a company is generally difficult to do unless you're an established attorney. The cushier 9-5ish hours are a big draw, and In-House counsel jobs are hot numbers for disaffected firm attorneys that want to get to know their children before they head to college. It will be very difficult to get such a job right out of grade school.
So you tell me: Is it better to work in a law firm than a company?