Pros
The overall compensation package including benefits is top notch. Shell works hard at bringing in talented individuals and places great emphasis on training and retaining that talent. I'm impressed with my colleagues' professionalism and creativity every week. 9/80 schedule ( every other Friday off) is amazing. Before I started, people would tell me that those who join Shell rarely leave. That may not hold quite as true as it used to but I've met plenty of co-workers who have been here 20 -plus years.
Cons
Career progression can be difficult in some sections. Be ready to try a new area in Shell after 3-4 years. Focus on opportunities that add skills to your resume no matter where you end up. As with any very large company there are lots of administrative tasks and processes.