Pros
You get a fancy name on your CV and a bunch of friends to share your misery with. You can have decent exit opportunities unless you want to exit consulting.
Cons
Work is very repetitive and not family friendly - especially when doing due diligence. You have a steep learning for 6 months and then nothing, except heavy workload. Engagement managers are told to do everything (managing projects, finding projects, mentor team members). VIPs in the organisation have unfortunately created a hostile environment and never had a reality check with HR for their management style. It goes from negative comments on dress code to clear threats that you will not be staffed unless you agree with partners' direction/project content. Coming out of MBA where debates and respect among students were mandatory, I got shocked by a sheep mentality and a certain bully culture that was tolerated in the firm. HR could not provide any help, "it has always been this way, and current partners learned it from previous partners" was their only response. The limited recruitment pool in London (MBA & Oxbridge) is certainly not helping.