FWIW, here's my workflow with DP1 files.
1. Convert to tiff in SPP. I use the Auto setting primarily. You end up with a fairly flat looking file, but you retain the most information in the shadows and highlights this way.
2. Open the tiff in PS and if necessary, apply a little capture sharpening using PhotoKit Sharpener.
3. Convert to B&W with Silver Efex Pro. I usually add a little vignetting here too.
4. Local contrast enhancement (known in LR as Clarity) using the Unsharp Mask trick.
5. Resize as required for printing or web, and output sharpen accordingly.
Obviously other tweaks may happen along the way depending on the image, but that's basically it in a nutshell.
Bill