Pros
UL tends to operate like a standard nonprofit. That means you have a lot of flexibility in what you can do, and that ideally you are able to climb the ladder if you have enough business smarts to do so. They are obviously working towards safety standards as a company, so you are actually working for a company that is actively trying to improve the world. People work here until they die from old age. IT staff are extremely knowledgeable, skilled, and basically keep the company afloat. Hours are reasonably flexible in most positions. There are lots of extracurricular activities around the main HQ (volleyball, basketball, soccer).
Cons
UL tends to operate like a standard nonprofit. So, that flexibility will mean you will be handling things far outside your job scope. This means degreed individuals (esp masters and are given far more specific scopes (and less responsibility /more pay) to do the exact same thing. It is explicit that pay correlates to degree, often by more than 20%. So if you don't have a higher degree but bust your butt, it won't matter come review time nor will it matter because UL pay for those without a degree is beyond uncompetitive. Average entry level positions will pay around 30-50k in careers that usually pay 50-70k. Typical business management is awful, full of nepotism in all the bad ways, and believes that working harder is preferred to working smarter. Salaries do not grow here from where they start, so make sure you start on a good salary or you're going nowhere. I've doubled my salary simply leaving this company. Also nobody gets fired except bottom 10% during cuts, which happen every few years.