jayzee,Ordinarily, I would agree with the view that MBB is a great career accelerator and you should take the opportunity. Amazing exit options. Surrounded by some of the brightest people. Etcetera, etcetera.But, since you are in the mid-30's with young kids, it is very difficult to appreciate the high bar of expectations these firms will place on you.People perceive pressure in different ways, but you will be under a constant push for output, insights and client impact. You have to earn a reputation for excellence very fast. By that I mean, you must earn it in your first case, maybe your second. After that, you must maintain that reputation. If you screw up, people are written off very quickly. And they have a fresh new, hungry class right behind you. That is why 'up or out' works so well. People are paranoid about underperforming and give their everything ... all the time.Don't get me wrong, the people are great and very nice. But you must walk into this structure / system with eyes wide open.