Pros
It's great to work with good people, committed to improving they way they do work. And I appreciate that I always got to work on tough problems that would have an impact to client decision making or to the way the client did their work. It's an invigorating work environment. Also, the lean organization meant that I always had opportunities to build business skills that would otherwise not be possible at a major system developer.
Cons
The lean organization and high leverage meant there was always a lot on the plate. You were given good frameworks and some tools, but you kind of have to take care of yourselves to a certain extent (with regards to, e.g. recruiting, specific skills development, business development, etc.). This is part of life as a consultant.