I can second this. We've been with Zenefits for over a year now and the issues don't stop. Many of their "integations" occur in meatspace: when a change is made on the Zenefits dashboard, a Zenefits employee then manually updates the related service(s). This has resulted in a number of errors over the course of a year.

Additionally their are still issues with validation on their dashboard. We had a problem where the dashboard allowed an invalid value to be entered for a monthly 401k contribution that was a big pain to unwind.