Pros
Exxon is at present a stable company with solid benefits. There are locations in many different areas and if you are willing to move, you will likely get the opportunity to do so. There are opportunities to move between the different business divisions (chemicals, refining, lubes, pipeline, E&P) in order to develop a well rounded employee, however unless you are tagged early as a rising star or top performer, opportunities may be limited. The stock match of 7% for our 6% is a nice perk. If you are extremely aggressive in self marketing or like sucking up, it's a great place to advance.
Cons
Forced rankings mean the suck-ups usually out perform the competent, hard workers. Much of the culture is the holdover from Exxon more so than Mobil. Exxon is a very Engineering lead company and therefore views people as resources rather than assets to be invested in. Supervisors are asked to evaluate their employee's potential when they are first hired in. Depending on your supervisor's first impression, your 30 year career growth potential can be severely stifled by one bad review. There are many supervisors and managers that are victims of the Peter Principle and are now in the level of their incompetence with no opportunity to move any further until they retire.