Pros
Very challenging and dynamic work. You have opportunity to quickly take on roles of increasing responsibility. Consult on different types of projects at different companies. Compensation package is pretty good (high salaries, profit participation, matching 401k up to a %, stock purchase plan w/ company match up to a %, decent amount of vacation days plus comp time and flextime, and other benefits (medical, dental, vision, short term and long term disability, etc.)).
Cons
Can be extremely stressful and too demanding. Project work is often a baptism by fire -- need to quickly figure things out and always present yourself as an expert to the client. Work days are very long. Need to be ready and willing to work on travel assignments (for example, on a travel assignment, you could be away from home Monday through Thursday or Friday (company pays for hotel, travel, and meals) for the duration of the project. Travel assignments can put a strain on family and personal life. There is a 3-week bench policy which means when you finish on client engagement, you need to be staffed on another client engagement in three weeks. Otherwise, you likely will be laid-off.