I believe the ideal scenario is when you are already using the Intuit family of products and the payroll bolts on to your existing QuickBooks infrastructure. Payroll software products have been around a long time, and this is a very competitive niche. Most of the companies do a good job of filing taxes promptly, reporting W-2 items properly, providing good reports, etc. Where you might really get some extra efficiency and benefit is the fact that the payroll is woven into the accounting system, creating one seamless enterprise solution. Also, where it might be less appropriate is in a really simple use case such as a one person company where there aren't complex fringe benefits to deal with. In that scenario, you can set up the ACH debits directly with the state agency and the IRS and possibly file your own 941, 940, W-2/W-3 and state equivalent forms. Of course, if you're willing to do this and are good with details, you can save yourself some money.