Pros
Corporate culture is friendly, depending on who works within your group. Benefits are pretty good, but getting worse rapidly. If you chase new internal certifications and external credentials (degrees from universities) you will be promoted to new work. When the economy is good, extra overtime can sometimes be rewarded. Work obligations seem based on what you get done, so if you work expediently/efficiently, you are making more money for less work. The dress code is relaxed if you work for the right people and aren't afraid to test the waters. Working from home is possible with years of time under the same boss, or with certain jobs.
Cons
Overtime is mandatory for many employees at many locations. If you make X dollars for 40 hours a week and they make you work 60 hours a week, you are really only making x(2/3)+x(14/40) which means you make less than they would lead you to believe. Politics can be brutal in some groups. Some groups are friendly, but the majority of them have a backstabbing factor, where you have to be very careful what you say in front of people.