Pros
There are alot of resources available to you -- from firm sponsored training to national tax specalists. They are usually pretty good with flexible work arrangements and encourage mobility and flexiblity.
Cons
Alot of administrative red tape - professionals will find themselves spending lots of time of adminstrative garbarge that non-professionals should be doing. While there's something to be said for having specialists and resources, maybe it's a little too siloed -- you end up with 8 different "speciality" persons on any given project. Senior Managers are expected to function like PPEDs, without being compensated for it -- and all of the development of staff/seniors fall on them and the managers. There is very little focus paid by PPEDs on development of personnel. Salaries among a given level vary widely and there is no transparency whatsoever. You are CONSTANTLY reminded of your utilization -- you hear about it if you do not meet your utilization goals and in the same breath your hours on a given project will be questioned. This focus on budget and utilization are in conflict. They are also horrendously bad with getting new hires integrated -- clearly they hire people who are bright and experienced and there's a need for them yet you have to "sell" yourself to a group for up to a year before you can get any work -- makes absolutely no sense.