Although the P85 has more measurable output than the P81, its frequency response and string interface are different. The P85 uses two Alnico V magnet loaded coils in a P-90 style housing which provides a wide aperture to maintain a beefy low end and a more expansive top end. This pickups has a great natural tone and works great as a rhythm and blues pickup because it has loads of warm output but isn't muddy. It's a perfect choice as a rhythm pickup in combination with an P81 in the bridge.