Avantages
They seem to never fire anyone, so even if you truly suck at your job, you'll be safe for at least 6mo to a year.
Inconvénients
The management is awful. They will pay you as little as they can get away with (that's why I left, I couldn't afford to continue to live on the penny's they offer) it doesn't matter how good at your job you are or how hard you work, they like to play favorites, and you only get recognized and rewarded if you're friends with the partners or at least higher management (even if you don't deserve it, that was the worst part, the people getting paid the most and getting the largest bonuses were also the worst employees, at least in my old department)
The atmospher is depressing and stressful. They like to punish people just for talking to their coworkers. I understand not wanting to waste company time and money on idle chit chat, but it was like working in a police state most of the time.
Basically zero chance of job advancement. No one ever moves up in the chain, and if you do manage to move up a spot, they don't give you any kind of pay raise or extra benefits.