Ventajas
Merrill is a challenging and fast moving environment. You work with smart, motivated people, occasionally on interesting problems. You usually get to see what you do have a real and almost immediate impact. Also, the 'interesting' management style (see below) does leave you with a lot of freedom. Oh, and not to forget, you can get paid dirty great piles of money.
Desventajas
The management style is sadly best described as Ready, Fire, Aim. The senior management is still recovering from a cleanup following the departure of Stan O'Neil, and in certain areas does not appear to be up to speed yet. Staff turnover is also high, perhaps higher than other industry members - I have heard Merrill Lynch described as a revolving door more than once.