Stable high earning income and the people you work with on the day to day are great. Cheap union healthcare. They buy your lunch/dinner if they force you over.
Svantaggi
Forced 8hr overtime with incompetent power tripping supervisors and company men. If the foremans or subforemans dont like you personally they will invent write ups for vague violations. It doesnt matter if those violations arent in the handbook the write up trumps all.