Pros
Great benefits, everyone is professional and very welcoming, all the seniors are always happy to help with questions and your learning development. It is a place where you take full responsibilities of your own future and development in the company. Everyone is entitled to training budgets annually, and that means every year you will learn and grow.
Cons
The other side of the coin of a high performing environment is that a competitive environment may also exist. It is up to yourself to take that as a positive challenge or not. Benefit wise - it is not as good as 5 or more years ago. Regardless, it is still among the best among other companies in the same industry. Finally, Shell has a tendency to overcomplicate things and making a lot of terms/phrase/jargon into abbreviations. It may take some time to familiarize with it.