Pros
Wonderful benefits, work/live balance is the best I've experienced, leadership is mostly casual and not hell bent on squeezing every penny out of the bottom-line or squeezing every second of work out of their subordinates. You are also not inundated with "group think" training which seems to have infested many similar-sized companies which is outstanding - I want to do my job, not worry about the bleeding edge political correctness that is trending every week. Don't get me wrong, LM is inclusive, but they aren't shoving it down everyone's throats 24/7 which is a really nice change of pace.
Cons
Easy to get lost in the size of the organization. Difficult to move around. There are people who are "riding it out to retirement" who do just enough to not get fired - but I guess that's everywhere.