I retired from the industry just before line arrays became the defacto standard. While I have never worked on one, I have heard many in great sounding rooms and outdoor concerts with some of the best artists and music that should have a high degree of fidelity-- Genesis, Tina Turner, James Taylor, Dixie Chicks, etc.
I have to say that I have never been impressed with the sound I have heard. In some cases with bands like Genesis which I have seen many times throughout the ages, I have to say they sounded way better on some of the older systems in the exact same venue.