We're really happy with Gusto. Employees find the onboarding process smooth and intuitive. Management of employee documents and digital signatures is very easy. Support has been good (although we do have an outstanding issue on a tax issue that they have yet to address - presumably their tax team is overloaded with end of year initiatives). But generally I've been impressed with their support. We don't use their benefits administration, but the integration with our 401(k) plan is smooth. They don't currently have an integration with Performance Management tools, would like to see that in the future.
+1 for Gusto. We've had a good experience (with only a few customer support touches required) even with employees in multiple different states. Payroll is easy and we use them for our benefits as well. They keep you on track with all the various deadlines, signatures, etc. and all of the tools are easy to use.
Used Gusto when they launched. Very buggy, had tons of issue with their compliance filing and a bunch of fees and penalties from different government agencies. Used them with another company once they were a more mature product, generally works better if you have a simple structure such as all W2, domestic employees. Not the greatest for hourly. 1099 works ok. Moved to Rippling with the third company. They are more expensive, you can get 30-40% off their list price with a little prodding. It's a bit more complex of a product, a bit overkill for an early stage company, but it has a more integrated flow for w2, hourly, domestic, international. I went with Rippling so I wouldn't need an HRIS, so basically lumped the cost of payroll and HRIS together, which comes out to about Rippling. They also have a PEO at 5 employees that I'm waiting to test out. Rippling sales team isn't great, don't think they spend much effort here, but the product is good.