Pros
The pay is above industry average and includes paid overtime. The benefits are among the best in the world - generous 401(k) match, healthcare plans, PTO, and educational reimbursements. If you work here a long time, you are guaranteed golden handcuffs. You will be almost immune to layoffs due to the union, your PTO only gets better with service, and you get minimum annual raises, even if you are a low-achiever.
Cons
The culture at Boeing is indescribably poor. Much of this is a result of the union. There is extremely low differentiation amongst employees. People who work their butts off receive marginally higher raises than those who do nothing all day long. Laziness that would result in immediate termination at other employers results in no action from Boeing because the union makes employees bulletproof, except in times of extreme layoff. It is better to look good than to be good here. Boeing hardly cares about the results you generate. Success is measured by showing up on time and being present in your chair for 8 hours a day, regardless of if you do any work at all during that time.