The biggest advantage of doing BigLaw IMO is that it's on your resume for the rest of your career. Every job I've had since my big law job has been the result of having BigLaw on my resume. And now, I make a decent living working family friendly hours remotely in Utah for a New York company.

The biggest disadvantage is that you will likely have no life during your BigLaw tenure. Your days will be long (especially if you have to tack on a long commute). You will be "on call" to work evenings and weekends. You will likely pull some all-nighters. You will have no vacation time. You will probably have to deal with abusive partners. You will often feel like an absentee husband and father.

Along these lines, you can't really appreciate what this is like until you live the day-to-day grind of it. Trust me, it sucks.

For me, the payoff was worth it in the end. But it was rough and I wouldn't want to have to do it again.