My workflow varies between:
1. Downloading the raw (NEF) files directly from the memory card to my hard disk.
2. Using the DNG converter to download and convert the files from the memory card to my hard disk.
When looking at the metadata embedded in the image files (ExifTool) I note there is a large amount of data present in the .DNG files which is absent from the .NEF files. Presumably this data is added by the DNG Converter. I am particularly curious about the data relating to Camera Profile. Can anyone enlighten me about the source of this data?
I haven't ever looked closely at that metadata. But as far as the camera profiles are concerned, Lightroom nor Camera Raw are able to read that camera profile information. Since you have a Nikon camera, you will find that Adobe has created camera-matching profiles. This enables you to assign any one of those profiles to your image in Adobe software.