Abusive Work Practices, Strong Sense of Entitlement, and Hateful Managers
Pros
Benefits are good. Compensation is good for union workers, but if you're in management they'll cheap out until you stand up for yourself (and then make false promises). Lots of opportunities. Many good people working at various levels of the company (but they get pushed around - see Cons).
Cons
No respect for employees on any level. Management often creates a hostile work environment even when there is no reason for one. Senior management comes up with new policies, often contradicting the union contract, and forces first-line supervision to implement. This puts the supervisors in a position of having to implement policies they don't understand and don't agree with or ignore them and risk getting fired. The company lost a lot of good supervisors and managers over the years who got tired of these antics. And if you're not in the union, they'll stick it to you for as long as they can on salary. When you find out your being grossly underpaid, they'll make promises to align your salary with your peers, but then when the raises come out they'll hem and haw about budget constraints. All the while they'll work you ridiculously hard and you'll find that your actual hourly rate is less than that of the guys working for you, but the company will tell you it's a good deal because you're in management.