We're a 5 person lab, been using QB for 20 years and are quite happy with it. We've never used a lab specific software.
We also use it for payroll. We used to use a payroll service but QB was significantly cheaper. I don't know that that's the case anymore.
QB is very good for communicating with your accountant. Ask them for suggestions on billing software.
We have been since 2012. We were thinking about adding on DentaLab for quickbooks, which is built on top of QB. QB standalone has been more than enough, but as we grow we do want a few more lab specific features.