Pros
I've been with the company for slightly less than three years, including as an intern, and it's amazing to recognize how much I have developed, both personally and professionally, during that time. I credit this to an extremely supportive, team-oriented environment and to being constantly challenged and pushed by the partners I have worked for. Also, you're constantly surrounded by incredibly smart people. In my previous jobs at start-ups, I enjoyed my time and liked my coworkers, but I've never before been so impressed and learned so much from the people I work with. (And this applies to people at all levels in the organization, from first year consultants out of undergrad to senior partners.) The new combination with PwC comes with both Pros and Cons (Lotus Notes...? Seriously...?), but so far, it appears that management has been dedicated to preserving those things that made Booz & Co. both culturally unique and high quality. Without making predictions about the eventual success, I think it's enough to say that at present, they are on a good path. (Also, it's worth noting that potential career opportunities and flexibility are much greater now that we're a part of the PwC network, especially for women who might consider going internal for a few years while raising kids.)
Cons
There's significant volatility of workload. Invariably, you will eventually have a final deliverable due on a Monday after a weekend you had planned to get away or take vacation. So even with you and your team's best efforts to balance your workload, you will sooner or later run into times where work interferes with personal time. However, I don't feel that our work-life balance is any worse than any of the other top tier consulting firms, and is better than some. (And much better than banking, for what it's worth!)