Professional development was below average. Managers are not compensated on how they develop the people below them. I encountered numerous managers who didn't even conduct one-on-ones with their subordinates (aside from annual reviews). Skip-levels are unheard of.
While base salary was decent, the bonus structure was inadequate. For the position I was in, 20-60% of base is customary, but M&T was offering 2-4% annual merit bonus.
The technology and systems at M&T are woefully outdated. They are probably 20 years behind the cutting edge financial institutions. This problem is emblematic of a general reluctance to undergo change. Pushing through any substantive change at M&T takes an act of Congress, so if you've got a lot of good ideas, prepare to be either stymied or have it take 4-5 times longer to implement your ideas than you expect.
Not to be overly nitpicky, but no coffee in the break rooms? C'mon! It's such a cheap perq that makes such a big difference.