Vantaggi
Great place to start career and build resume. Exposure to client management even at very junior levels. Lots of intelligent coworkers to learn from. Young workforce and easy to build relationships while working on 2-6 week stints with different people each time. Partner compensation is very attractive if you are willing to sacrifice your life and family.
Svantaggi
The most well rounded people always leave because the work/life balance is impossible and they value more in their life than a big salary and massive vacation home they never get the chance to use because they are working so much, or that they use but spend the whole time on their blackberry or working remotely. Everyone sees how much the partners work and nobody wants to be them these days (seem to still be using a 50-year old business model where everyone wanted to just just work for one company and get to the top - not realistic anymore). So the partner group ends up being a nerdy bunch with little in the way of social skills, and/or egomaniacs. The audit practice is cyclical and very difficult to manage so they shortsightedly let people go in slower times when chargeability is down then are short staffed when it is inevitably busy again, leading to staff being overworked and unhappy and, again, the better people leaving. Cycle continues. Win a bunch of "Top Employer" awards by offering very obscure services/benefits that nobody uses. Audit practice is generally thankless as clients are not actually paying for something they want, only something they require. Client staff often defensive as they think you are out to find their errors and get them fired. Morale therefore hard to maintain. Can't win on budgeting/chargeability - either you are efficient and do a good job but are not chargeable enough or you are very chargeable but get heat for blowing budgets.