Pros
Excellent benefits if you have a family. Boeing has offices in many places and it's pretty easy to change jobs.
Cons
Boeing is a hardware company that also writes software. That means most management is trained for and think in terms of hardware, so they do little to keep up with current software trends or best practices. There is no real career track for software development. It is very hard to get past level III without taking a management position. Consequently, there are also very few experienced developers to work with and learn from. Additionally, since they are a defence contractor funding is tied to contracts and you have to track hours and charge to the correct number. Some software products that are used by multiple contracts are given very little overhead and this causes developers to have to charge to several different numbers on a daily basis.