Pros
The mission statement and company history is unique: to help make the world safer. I've seen examples of cheap products spectacularly fail basic tests, which makes my job feel worthwhile. Working hours can be flexible. Most of the people I work with are really nice, and competent. Over 14 years I've seen the leadership and culture slowly trend up towards a better working experience, but there's a long way to go. Some of the smaller fringe benefits are good.
Cons
The company size and organization hampers communication between divisions and creates a lot of confusion and barriers to getting things done. Middle managers lose sight of the mission statement, and average employees find ways to abdicate responsibility by throwing problems over the fence or generally slack off. I've seen egregiously poor work go unnoticed from lack of visibility or low performance accountability standards. Bad apples are left to rot instead of tossed out. During company-wide town halls, the CEO and HR say they aim to be 'at the midpoint' of the industry in terms of compensation and benefits. Well, it shows, because UL is an average company with average people. Medical benefits have also gotten steadily worse since I started (more expensive, and less coverage).