Vantaggi
Compensation - they need to pay well, as that's the only way that they can keep people for as long as they do.
Svantaggi
Everything else - I was part of the operations team for the Chicago branch (which, I hear, has recently been closed and everyone laid off), and it was a daily struggle to merely come into the office. The Sales Manager was a walking Successory that had no substance whatsoever and would resort to threats and political back-stabbing if he were ever questioned. Most of the Sales team was great, and they tried hard, but had such little support, it was a losing battle. The consultants were treated terribly and were ALWAYS fired as soon as they weren't billable. There were also consistent issues with paychecks and/or bonuses not being right.