Pros
Learn about your market, the players, the trends, and get really good at talking on the phone and convincing people to do things you want them to do. Mostly fun and nice people. Some really great management. If you are successful, you'll be praised and promotions are closer than you think. Incredible database of the best bilingual professionals in town. If you can't succeed at Walters, you probably wont succeed at a competitor.
Cons
You'll pocket more money at a smaller commission based firm, for sure. Some really thick people you'll have to deal with internally, and politics whether it management, accounting, or just other consultants If you've experienced recruitment at a commission shop or other countries, it seem like a slow start for you.