Pros
The main pro to me is a benefits package which is good compared to many US employers- they offer medical, vision, dental, all kinds of pets insurances and childcare benefits... In my experience, too, the vast majority of people are ambitious, professional, and willing to help, but depends entirely on what team/business unit you're with (more on that below)
Cons
There is absolutely no sense of everyone at Cision being part of the same company. Historically, everyone has operated in silos. New management is trying to change that, but that sort of cultural change takes years. Don't expect to get to know many people outside your immediate team and office for now. Because of this rift between Cision's divisions, employees continue to communicate inefficiently and spend time and energy saving their work in 5 different places and hunting down things that should be available more easily.