Pros
We eat our own dogfood - The best benefit of working here is by far the generous, company funded retirement annuity which you are fully vest in after 3 years. The company contribution rises progressively with your age, maxing out at 13% of salary a year around 50. They also match 100% on the first three percent of savings in your 401k. How many companies offer this sort of valuable benefit any more? Very helpful in building a secure retirement. Anecdotally, TIAA is less "Dilbert"-like than most companies of this size, though human resources has recently exhibited disturbing trends in the wrong direction.
Cons
TIAA is a insurance company. It is not a high tech firm, or a company that likes to take risks. Depending on your point of view, this is good or bad. For me, a self described IT Professional, I find it a challenge to feel like I can make a significant contribution since the "business" views IT as a just a cost center. The IT folks they hire are smart, but their work efforts are fractured and disorganized due to a lack of organizational maturity. If you are expecting the latest in IT best practices, you will be disappointed.