Pros
You work for a company that is well known. Pay seems to be average perhaps even slightly above average depending on the role. MetLife pretends to care about their employees. It's nice to feel valued. Having said that, feeling like you're valued and actually being valued are different things. Once you realize actuality there aren't many pros to mention.
Cons
MetLife is in a "transitioning" state. What I mean by that is, they don't know where they are at or where they are heading. They want to be a tech company, they want to be an insurance company, they want to be an investment company, there are too many cultures to count within one organization. Executives are incompetent, they got to where they are through the "Good Ole' Boy" program. Their sentences are full of buzz words, and the people next to you are only concerned about self-preservation. Accountability is not something that is required, so you can simply get paid to not do a thing (and that's who stays at MetLife for years). If you are hoping to advance yourself, don't expect your work to get you far. Politics, politics, politics. Just another large company where most people are small fish is an incredibly large pond.