Pros
Work life balance is a big plus here. As long as you are not onsite, you can usually work from home. Most employees get laptops they can take home. Culture is great and the annual review process is the best in the business.
Cons
Compensation is lacking and there are large discrepancies between pay for people at the same level. Ceiling is at level 3 - forget making it to level 4 unless you can generate a ton of business. Over the last few years Booz Allen has turned from a true consulting company to a government "staff augmentation" company. In other words, you may be exceptionally smart with a great pedigree, but your boss may sit you in the basement of the Office of Veterans Affairs answering telephones just so they can maintain their productivity numbers. Don't believe that you can move around freely within the organization. Most managers would rather hire (and boost their team numbers) then take on someone from elsewhere in the organization.