Pros
I joined Boeing 18 months ago looking for an employer that was engineering interesting products and that valued quality engineering. Boeing for the most part does these two things well. The quality of the engineering staff is generally excellent, the work is interesting (particularly in Phantom Works), the resources and tools provided to the engineering staff are good but not excellent. Good benefits when compared to other defense industry companys, but only average when compared across all industries. Great place to work for recent grads starting an engineering career. The fully paid advanced education benefit is excellent.
Cons
Don't be suprised if Boeing's initial offer seems very low. If you are experienced, submit a counter offer. The two largest concerns for me are performance recognition and advancement opportunities. I joined Boeing as an experienced engineer, taking a pay and grade cut when I accepted Boeing's offer. A year and a half later and I'm still the same grade and nearly the same salary, even with my manager stating that I should have been hired in one grade higher. The performance management process at Boeing is broken, which is great for an average engineer, but terrible for the high performers. Managers are very constrained on the pay raises they can give to their employees and in-line advancement is done by committee. Boeing is also going through cost reduction exercises with intentional reduction of advancements above grade 3. In-line advancement beyond grade 3 is difficult and beyond grade 4 doesn't happen. For experienced staff, Boeing requires applying for a new position and these positions are often open to external candidates, so they are competitive. It is unclear if Boeing gives internal candidates any preference in the hiring process. It is no different to applying to another position at any other company, so there is little incentive to remain at Boeing if you find a better offer elsewhere. Tools and methods in some disciplines, like structural analysis, lag behind those used in other industries. Boeing doesn't pay for training beyond grade 2, it is on your own time. The engineering responsibilities are strictly separated (particularly loads, dynamics and structural analysis) which leads to engineers who are not well rounded.