Pros
People you rub shoulders with are genuine (in most circumstance) Benefits are ok, not the best, but good enough and they pay for medical insurance One of the best companies to get a broad range of experience and learn from many people.
Cons
Below market salary (they convince themselves that they pay the market rate) Horrible senior management that only focus on thier billables, I don't blame them, but if they don't meet targets, they move to redundancies. That's the big 4 way. The current market does not favor generalists, so moving from Deloitte will likely be a struggle unless it is to another consulting company. Secrecy and hiding information is a big part of high level management, often catching contributors off-guard and damages trust.