Pros
Management seems to care about people, especially if you become one of the chosen few. A lot of exposure to interesting projects as Clark is the undisputed leader in the DC area. Recognizable brand name.
Cons
Most people are overworked and underpaid. Management can't seem to make any decisions, and go as far as to promise things and never deliver. On one hand they don't get rid of people who should be let go, but they also don't promote people and allow staff to stagnate so the ambitious people leave. Anything other than straight construction is not a priority (green building, water, energy, P3, etc.). Clark hires a few hundred new college grads each year and loses most of them, as there are very limited opportunities to move up, with the exception of slogging it out and waiting for your peers to quit leaving you the only one to promote.