Pros
You will get exposure to different industries and a basic understanding of how companies operate. Protiviti management generally consists of good people who treat you well. Junior level employees get a good amount of responsibly and Protiviti invests a lot of money in training. Overall, you will learn some interesting things & make good friends.
Cons
Companies hire Protiviti as a vendor to complete specific tasks (SOX, IA, IT security assessments), rather than as a firm to provide groundbreaking analysis and creative insights to improve the business. The work is audit focused and the majority of employees (especially those out of college) will spend their time doing SOX control testing and internal audit. In these rolls, you are providing assurance that the business/ people are following the rules and performing their tasks correctly.