Pros
Important note: this review only covers employment at a collection center - the corporate office could be an entirely different story. At the time of this review (Q4 2014) CSL is in a phase of extreme growth. This translates to numerous opportunities for advancement, especially if you're open to relocation. Support structure at the regional level tends to consist of knowledgeable, compassionate managers.
Cons
As other reviews have mentioned, compensation is low across the board. Over the long term, this results in a lower-than-average caliber of employee, in terms of education, motivation, and raw talent. The job market may be bleak, but the real assets tend to find their way out to greener pastures eventually. Being such a huge company, the culture can feel a bit dry - to everyone but the people you interact with on a daily basis, you're no more than a cog with an ID#.