I use Substance Painter to make materials. It's internal render engine is iRay. I use the maps created in Substance on Poser's Physical Root. There is no visual difference between the results of the iRay render in Substance and the Superfly render in Poser as they use the same maps and can use the same HRDI environment. The same maps, on the same objs, with the same lighting, gives the same visual result. The only difference is in the time it takes to render and there is no way I can compare them as they are two separate pieces of software. Is that not the purpose of a PBR? Consistent results across platforms regardless of engine used; because the physics of light does not change just because some software company says it does in their render engine? That is why I use Substance. PBR materials that look the same regardless of the render engine used to display them. Until either Poser or Studio start rendering with both engines you have no valid comparison of render times.