Pros
The company is very stable (read: boring) and it's hard to get fired. You can move to other parts of the company pretty easily as long as you're qualified and you have a good reason, as they really do want you to be providing as much value to the organization as possible. As long as you have a manager who doesn't micromanage you and you don't dislike the work you're doing, it's not too bad. If your goal is a stable job that will pay the bills, M&T will definitely cut it. They give you a very generous amount of time off, so work/life balance is almost never an issue (except finance where typical work hours are 10-15 hours a day+weekends). People here are friendly and family-oriented. You can pretty much work here for the rest of your life without worrying about losing your job.
Cons
Senior management is full of judgmental dinosaurs and is still a boy's club. Managers are managers because they've been at the bank for so long or know the right people but are not always great leaders. There is no room to promote. There are way too few positions for higher level managers so there is no motivation to do great work for the company. Raises just match inflation, if even. The difference between ok work, good work, and great work is pretty much nothing in terms of compensation and bonuses. It will usually take you at least 8-10 years to get into a managing role. Employee engagement is a joke and compensation is severely below industry average. You're going to hit a brick wall if you're the creative/ambitious type and your goal is upward mobility. The attitude is "we've been doing it for x years and it has worked for that long; why bother with change." Yes it's a bank - and banks are highly regulated. Unfortunately, since no one moves to Buffalo unless they have family there, people tend to cling to the same old outdated ideas and technology. The company will continue to get trampled by regulators asking them to improve process efficiency. If M&T does not adapt to the changing environment, it will continue to lose talent.