Pros
Union Pacific offers very competitive pay and benefits, especially for the midwest. The culture has significantly improved over the 15 years I've been with the company. The newer senior leadership knows how to run a company effectively and is in tune with it's people, it's not your grandfather's railroad anymore. The retirement benefits are best in the country. There's a surge of younger employees which is great for the culture.
Cons
There can definitely be some long days, especially for field operations. Although senior leadership constantly tries to address this issue, it will always be an issue. Heck, it's a railroad that runs 24/7 regardless of holiday, weather, etc. If you're able to accept the working conditions, you'll be happy with everything else!