Pros
Working at Exxon Mobil is like living at MIT. Your colleagues are the best of their business in the entire world. In my 13 years there I was still blown away by the quality of my colleagues. Management is another thing, though.
Cons
Exxon uses the old "forced stack ranking" method for employee assessment. Your time there is like playing in one of the survivor games on television. A certain number of people will be fired every year Every employee is ranked in salary grade and a percentage will be fired every year. Thank former GE President Jack Welch for this idea. It has been the ruin of most of America's industries for a long time now. If Exxon hired 100 Nobel Laureates for a project, after a short while, half of them would be considered "below average." It all comes from a basic misunderstanding of statistics caused by sampling bias. Interns and short-term employees will not see this, but as you hold a job longer, it becomes a superb way to get rid of older, better-paid employees.