Pros
Boeing is very supportive of employees - my managers have always pushed us to apply for positions to help advance our career. You do have to take charge of your own path, though, and market yourself. The pay and compensation are fair for the area. Many of the employees have been there for a while, which can be a pro or con - managers at lower levels (slightly below senior management) tend to be home grown, so they understand what the employees are really doing. Their Learning Together education program is a great way to advance your personal skills.
Cons
It is very difficult to change career paths once in Boeing. If you enter in one field and wish to go into another, Boeing does not help you do so. Despite their Learning Together program, Boeing does not make it easy for you to take newly acquired skills into another career at Boeing. Management changes often, which can be disruptive to work.