MBB in NYC - experience with hours, work-life balance across the firms post-MBA

Hi all - I'm currently doing an MBA and have summer offers from MBB in NYC. I am trying to get underneath whether there are significant lifestyle differences between the three firms. I know that I will work hard at all of them, but I am wondering whether there are concrete differences in:

• hours worked at the different firms
• competitiveness amongst peers
• the degree to which management supports you in protecting 'balance'
• and the degree to which management cares about 'fun,' 'happiness,' and 'team culture.'

I am finding that some of the firms do a much better job talking the talk on this stuff, but I don't know how much that translates to an actual difference in the experience I will have. It's hard to cross compare b/c few people have worked at more than one of the firms.

I'm a woman and thinking of having a kid fairly early in my tenure, so if anyone can speak to that, I'd also love to hear about it.

I have a favorite firm from a people perspective. It is also the one with the worst reputation on these issues, and I want to know how much it actually matters.