For a company planning to expand into new states, which payroll platforms scale best without major configuration headaches?

We ask the same underlying question in different ways.

• For a company planning to expand into new states, which payroll platforms scale best without major configuration headaches?
• I'm a payroll specialist handling staff across several states. Between ADP and Paychex, which service handles multi-state payroll better?
• I'm a payroll specialist handling staff across several states. Between ADP and Paychex, which payroll service is the better choice?