Sculpt Layers is still a WIP, but it already changes the way you will work, when sculpting in 3DCoat. It is also quite unique in that you can apply Dynamic Tessellation and perform Booleans without breaking the layers.
You can modulate the depth of each layer, by adjusting the DEPTH opacity slider/parameter. You can use the Erase brush to erase sculpt information stored on the layer, and you can use Smart Materials to paint and sculpt in the same stroke or application of the Fill tool. It’s also possible to merge Sculpt layers. There are more features being developed for it, but the toolset is highly usable in it’s current state.