I've worked at CACI for almost 19 years, with the same manager. The company offers very competitive benefits and really takes care of it's employees. CACI also has a lot of opportunities for employees to move around to different contracts to accommodate personal or professional needs.
Cons
Some bureaucracy, but expected. Larger companies are inherently less nimble that smaller companies. CACI has done a fair job at taming this.
CACI has acquired quite a few smaller companies under its larger corporate umbrella, and although they have stripped these smaller companies of their identities and benefits thereafter, they do provide the safety net that larger companies do provide, but the benefits remain on par with most large defense contractors.
Cons
If you're apart of a smaller company that is either acquired by CACI, or have joined a program that once was a part of a smaller company already absorbed by CACI, you'll slowly watch the people, culture, and identity of that program drift away into corporate nothingness.