Pros
Good pay for low-skill fab workers. Decent work/life balance if you aren't an exempt employee. Frequent opportunities for travel if you are an engineer or manager. ON is actually a good employer if you're in SE Asia or eastern Europe. Not so much for US employees.
Cons
Compensation/benefits are low for skilled professionals, making it hard to retain good employees. Burnout is very common, especially in younger employees. The turnover is insane, even in middle-management. There is a huge disconnect between senior management and the people that actually do the work. Managers do not want responsibility or accountability for anything, so getting them to commit to any project is a huge chore. Senior management is also way too reliant on metrics in areas where metrics alone won't tell you what's going on. Even when metrics are given proper context, most managers still operate off of the raw numbers that tell them only what they want to believe. Regular employees are referred to as "resources", not people, and they're treated as such. Communication and cooperation between departments is very poor. Negotiating raises and promotions is mostly futile unless you have serious leverage that you're willing to use and you stick to your guns. The business side and a lot of manufacturing is located in the US, but most of the IT department is in eastern Europe. That works about as well as you'd expect. So many pointless meetings. So, so many pointless meetings.