Pros
I must admit I was wary of joining Facebook, after all the public scandals like Cambridge Analytica, moderators' work conditions, etc. From the outside, it seemed like an evil company eager to make money by exploiting masses. I talked to a lot of people before accepting the offer, and they convinced me I should give them a chance. I don't regret it at all, as internally you can see how everyone's trying their best to make this company useful for society at large (yes, making money at the same time, but definitely not as the primary driver of decisions being made). In the end I found a job where I got a significant salary boost, I'm tackling very interesting research problems, and work with people whom I appreciate and whose technical expertise I can trust. So I'm very happy with my choice! :)
Cons
The main drawback is the public perception of the company. But as I mentioned the reality is a lot more nuanced than what you can read in the media.