Pros
Competitive salary and benefits (from my experience). Work Life balance can be good if you can turn off your desires to execute good work and resign yourself to disorganization and mediocrity.
Cons
Publicly traded company, so mass layoff occur when work isn't being won. As the title suggests, I believe the work experience will largely depend on your Sector, Office and Manager (as it would in many other large companies). Oil & Gas is a chaos. Too many chiefs, too many egos, too little organization, poor planning.... In terms of internal processes, what is right one day will be wrong the next, or maybe still right depending on which manager you talk to. You never really know. This could be said of many large corporations to some degree, but this is worst I've experienced in my professional career. I would never recommend.