While most DLSR manufacturers prefer to export their camera raw files in their own proprietary format there are a few manufacturers that use Adobe’s proprietary Open DNG format as their native RAW format, they are: Pentax, Ricoh, Casio, Leica, Samsung and LG.
A DNG file is a proprietary Adobe file that suggests that it can convert other camera raw files at a size savings of 15% – 20% without any loss of quality. Another advantage of using a DNG file is that any editing changes you make with Adobe Lightroom (LR) are automatically written to the DNG file as well as the LR catalog. This way if the LR catalog gets corrupted (and it will) you can simply delete it and read in the DNG files to restore your edits. This is a good thing.
What’s the bad news? There really isn’t any provided you never change to any other software other than what comes from Adobe. Why is that, you may ask? Well, apparently specific camera profiles are stripped out of DNG files, unless the camera you’re using outputs DNG files as their native raw file format.
However, if you ever decide to switch from LR to another raw file editor, such as ON-1 or Capture One, you may run into some issues. Realistically only a very small percentage of photographers will notice a difference. Native camera raw files contain camera specific profiles, unique too and associated with each camera model. The DNG file replaces these camera specific profiles with their own AdobeRGB profile. While AdobeRGB defines a specific color space that is greater than sRGB, it IS NOT camera specific like native camera profiles are. Does this really matter? Only you can make that determination.
Here are three links describing the reasons some people stopped using DNG files or why they prefer DNG files
Read the articles and decide for yourself.