Pros
Solid top performing organization with a great reputation and a lot of employee benefits. Salaries are highly competitive and there are job opportunities in almost any location you'd like to be. The company does change with the times and embrace new platforms and technologies, but when you are as big as ADP with as many clients as ADP, change does not happen overnight. If you're willing to work hard and be the best you can be, the rewards will come.
Cons
Upward movement can sometimes be slow for those with fast track minds, but the reality is that people who are stellar performers and have or acquire the skills for the next level to zip through the ranks in short order are rare in any organization. Many business units operate in silos still.