Setting up nodes can be time consuming, but for most materials the only root you need is the Physical surface root which you can plug your textures into. At least as a starting point its very powerful. Metal, glass and water are very good in PBR but isn't that just good? Its hard to render anything without there being some sort of metal or glass at some point.

This is two images of a basic bowl from poser on a plane, one using standard Firefly material and the other a standard physical surface node. I think the difference between them is huge when it comes to quality, especially when the only difference is the render engine and the root node.

The Firefly render is rendered at very high render settings with indirect lighting. The biggest issue as I see it with PBR renders are the amount of time it can take to render if you are using wrong settings.