Pros
Diverse exposure to geographies and sectors, opportunities to move around / grow within the org. Pay can be good if you fight for it, very smart employees, fast pace. Can be a kingmaker for some people with enough luck & grit,
Cons
Extremely political - conflict is not only not resolved by management but often actively encouraged. Very clear dual class system where M&A and a few satellite teams are class A (high pay, carry, leadership roles, decision making, etc.) and everyone else is class B (grunts). Management is extremely disorganized. If there is a coherent strategy it's certainly not shared broadly among the org. Lots of smokescreens / obfusctation in internal & external comms. Need to fight for every nickel, don't expect anything you haven't pried away from management.