Pros
You get to work with some of the smartest people in the world, and your work directly contributes to the collective knowledge of humanity. People here do not see national borders, nor politics, and they don't see any challenge as unsolvable. The benefits you get at the lab are almost unheard of in the private sector.
Cons
The lab is funded by the DOE, so you will not be paid at market value. The leadership team has been mostly absent from the world. Top-down communication is awful. Technical debt is immense, technical documentation is scattered between divisions, even teams - knowledge is everyone, but everything is hard to find, and the docs are outdated by years. Individuals are overly specialized in their roles, and are in many cases the only person with full access to a system, this created an incident several months back where an entire project had to be put on hold for months because the team couldn't regain access to the developers repo, which it was stored on. 6 months after our annual reviews, our annual raises have yet to be given, and nobody knows when or if they will come, not even management. The lab is in a hiring freeze, with uncertainty on its funding not just due to political turmoil, but also mismanagement. Career development is essentially in a standstill. The only way to move up is if someone leaves.