Pros
If you're fresh out of school, Protiviti is a great place to start your career. They will give you the tools to become a successful consultant. Salaries are very competitive and are on the higher end to firms around the same size as Protiviti. Bonuses and raises are also above the industry standard.
Cons
The individuals in the Chicago office were very cliquish. There seems to be a "cool kid club", as well. If you didn't get in good with certain members of Senior Management (ie - Managing Directors), your advancement from Consultant to Senior Consultant, to Management, etc., will either be stifled, or you will be quietly forced out. Additionally, there are individuals in middle management who seem to exploit their title over their staff. This, combined with the aforementioned cool club, can be detrimental to those who don't "fall in line". The Chicago office's (and perhaps the rest of the organization) attitude: They have a big 4 mentality. They try to act like the Big 4, despite being significantly smaller in numbers. Then there's the work/life "blend". Translation: expect to work long hours, and expect to be at every beck and whim of your Manager/Sr. Manager. It could be 11pm in the evening, and if they email, it is the expectation that you are monitoring your email and are to reply in a timely manner. Don't expect much respect for your personal time, which is a result of the work/life blend described above. Finally, the periodic work from home (standard for the consulting industry) is frowned upon.