I have just released an update to my Substance Painter shader on BlenderMarket. The primary change is with the metallic side of the shader which has been redone from the ground up and in my tests produces greatly improved results. The dielectric side hasn't been altered however a lot of the shaders presets have been adjusted to hopefully cut down on post-import tinkering.
To purchase SP2Blend or download the update if you already have, please visit the product page on BlenderMarket.
The below image shows an example render of both the metallic shader and rim lighting influence old vs new:
Original v1.0 usage video
Substance Painter Barrel Tutorial