Pros
The working environment is collegial and there is a large support system in place - the "jerk" ratio, while not non-existent, is pretty low here. The base compensation is also generally fair and the benefits are good. There is a keen emphasis on employee development and many opportunities to develop and execute an employee development plan.
Cons
The thing you need to understand about CNA is that most (~93%) of the stock is owned by Loews Corporation and the majority of the board seats are occupied by Loews people. While this means the stock price doesn't fluctuate very much, Loews pulls a gargantuan amount of money out of the company every year. This was even moreso true during COVID when Loews's other businesses (mainly hotels) were in the toilet, so they declared a massive "special dividend" that was basically an asset redistribution away from CNA. Unfortunately, while it gets bled dry by its parent, the company has become curmudgeonly cheap. The new claim leadership is so miserly, it is impossible to get any investment, in people or otherwise, approved, because of expense ratio pressures. The present claim leadership is also very administrative, rather than technically, focused. Unfortunately technical excellence too often falls to the wayside in all the bean counting that goes on.