Slickly managed reputation; reality much grimmer...
Pros
Since it's the world's largest services firm, you'll find lots of colleagues and there will be many you like. The firm clearly cares about its reputation--here on Glassdoor, and everywhere else--so it does all the surface stuff to be well regarded.
Cons
NOT a firm of ideas. Never knows the difference between a good idea and a bad one; an old one and a new one; a valid one and a phony one. Impossible to find actual scholars at this firm. ENTIRELY a sales culture. That's what is prized here: selling multi-million dollar engagements, then delivering months or years of ordinary implementation work. Separately, it is a DO BE culture... Everyone is expected to be polite, enthusiastic, and to evidence a can-do attitude, even when they are being asked to do dumb stuff. This makes it very hard to be constructively critical in any way that leads to growth.