Pros
Generally the benefits and flexibility have been great (that seems to be going in reverse lately though, so I'd be remiss to just state that they are great). Individuals are great, there is a lot of diversity and the company truly is mission-driven. Paid volunteer hours are a great benefit that tie into the mission.
Cons
The incessant reorgs are bad for morale and momentum. I am on my sixth manager and third department in just four years. No amount of "change management" training makes up for that kind of inconsistency, at some point you have to accept that it's the change creators that are the problem - not people's hesitance to accept the change. Non-Charlotte and New York employees are not given equal opportunities for advancement. When HR tells you that you won't be considered for a role (that does not require on-site presence) because you aren't located in one of two offices (out of nearly 200 TIAA offices), you have a problem. People are having to move out rather than up. The work from home flexibility has been so important for work-life balance, however they are eliminating that benefit. Work from home is going away in favor of "collaborative" environments... when was the last time one of the people making these decisions had to sit in the middle of a cube farm and try to get work done? People literally tethered to their computers by noise-cancelling headphones isn't going to create the energetic, collaborative environment you think it is. It's going to wear people down and likely send them running. That's how you create a culture of "I work my 40 hours and then I stop caring."