Pros
It is a big old company. It is stable and predictable (most of the time). You will find old timers that has worked for the company for 20 years, easily. That means a lot of experience to learn from. It is an interesting manufacturing process, and if you are working in production, you will find that despite being over 170 years old, they are always innovating. Yes, if you have a PhD, you have space in the company, but if you have just a bachelor's or even a technical degree, you will also contribute to the development of the technology. There are even technicians with their names in patents. Great benefits.
Cons
Well, since it is big and you find people who have been in the same position for 20 years, you might not get a promotion soon. If you are not working directly in production, i.e., maintenance, procurement, pollution abatement, or facilities, your chances of being promoted or even making a lateral move are even lower. Those areas are not bringing money to the company/plant directly; in the best-case scenario, they are saving money, but that is a long shot. For that reason, you see people that is promoted after 2 years if they work in production, but in other areas, you find people that never been promoted.