Pros
Kleinfelder is like a jellyfish, in that it is made up of different, specialized organizations that all work together under the "Kleinfelder" banner. The company I worked for was recently acquired by Kleinfelder, and was allowed to operate much the same way they had prior to acquisition. This stands in contrast to other corporate acquisitions I've experienced, where the shift into the new corporate culture was swift and often harsh. Kleinfelder prefers a hands-off approach in many ways that preserves the original company's culture as much as possible. Kleinfelder aims to provide a corporate scaffold that the newly-acquired company can latch onto, and ideally, grow into.
Cons
Like any corporate acquisition, things never truly stay the same, As much emphasis and effort Kleinfelder puts into maintaining the inherent culture of a company, it's still a corporate giant, with all the limitations and failings thereof.