Pros
If you can become a high performer you are promised with really awesome work that is challenging and can be very creative. Shell has a tremendous amount of opportunities and can take you anywhere in the globe. The culture is very much based on "influencing" rather than "dictating" which can be a pro if you are good at influencing especially without formal authority. An employee can influence projects and work that provide significant value to the energy industry. Compensation is very competetive. Many people have 9/80 so every other friday off is a huge benifit. It is a very diverse & inclusive environment which is great.
Cons
Influencing can also mean that some work can be pushed down that may not make the greatest sense and can make it slow to get things done. During downtime it can be very bad environment with too many decisions of letting people go that should not have been.