I know there are a lot of disbelievers out there. I was among them (before I got into it). The first truth is that in corporate law your experience may differ greatly based on the law firm, lifecycle of the deal, client. Really there are a lot of factors that go into the calculus. The second truth is that for most people, the biglaw experience is worse than one expects. There's a reason why burnout and attrition are so high, why you hear about biglaw lawyers leaving the law, or lawyers leaving for any other gig that pays half of what they make. If they weren't desperate to get out, they wouldn't leave.
Additionally, I would say my friends at other non-NYC law firms probably worked on the order of 60 hours a week, with less weekend work. Their workloads sounded trivial to me coming from a v5 firm (and I was jealous of them), although compared with a normal job, they aren't.