Pros
Lots of work, so you don't have to worry too much about staying billable. However, the good opportunities are hard to come by (i.e. ones to learn and advance, work reasonable schedules, get recognition for your work). I've heard other offices are a lot better to be in than HR.
Cons
It's not a friendly office environment. People are very competitive or completely checked out. The main problem is the way they setup 'supervisors.' Most junior staff do very little to no direct work for their supervisor. It's a once a year meeting kind of thing, with supervisors taking no interest and never 'going to bat' for people getting raises/advancements. Also yes, as others have noted, the management changes frequently in this office, I don't know what it means, but it's not good. Your billability goal will be much higher than similar companies. You are pretty much expected to work overtime to meet these goals.