Pros
Senior financial management is very capable and keeps the company on as sure a footing as a banking organization can have these days. There are many who have found it a worthy place to work for 40+ years. The primary business is banking, so those bank holidays are a nice plus. Job security is probably higher than most, even for the mediocre. The brand is well-respected.
Cons
Relatively high job security means that the place is crowded - often with no room for advancement. It is also more highly networked, because of the long tenure employees have. This means that merit plays a significantly diminished role in hiring and promotions. Development of employees is not a priority, likely due to long tenure and a crowded workforce. The most talented and ambitious tend to move on.