Pros
At Boeing you will hardly ever be expected to work more than 40 hours a week. Boeing provides a pretty liberal vacation/sick policy compared to a lot of companies I've heard about. The retirement benefits are pretty decent despite the recent changes, however for new employees there is no longer a pension plan available which makes working here less worth it in my opinion. The same goes for the education programs. They used to be top-notch, but because of the recent changes they are as decent as many other companies within my field now. They also changed their health care plans recently under the guise of "even before the recession, we had a top-notch plan compared to our competitors". Probably the biggest benefit of working here is that it's pretty stable. Even if a program gets slashed, they will find a new place for you. The St. Louis facility is mostly military projects, so it's all funded by government contracts.
Cons
Boeing has all of the typical big company pitfalls, such as lack of communication across departments (especially across different sites within the country), lots and lots of red tape and bureaucracy, too many middle management positions that need to be slashed but never will, so much overhead that you find yourself spending at least a good hour or two a day dealing with overhead BS at your job (whether it's useless training courses, etc.). This place is very baby-boomer heavy as other posters have mentioned. They are a few years away from retirement. Boeing is very good at making up its own terms and its own initiatives and never following industry trends for software engineering for example. Lots of processes need serious revamping. This company has an extremely change-resistant culture. People are very used to doing things the same way they did 20+ years ago and would rather never change it despite today's rapidly dynamic economy. Over the years, I have seen many people attempt to introduce recent industry trends into the particular group. It's all started but then dies out after a few months. Depending on where you work in the St. Louis facility, many of the facilities are just awful. You don't even have your own cube unless you're a manager. The area Boeing is at in St. Louis is just slummy and depressing. There are a ton of people in this place that shouldn't have a job here. As said before, too many middle management positions and there also tons of people who spend the majority of their time on the Internet during work here.