As well as the long term archival question, also consider the portability of transferring metadata between the different applications you'll use over time (metadata embedded in a DNG is much more portable than in a sidecar file), the safety of letting any app write metadata directly into an image (safe with DNG, a guess with raw),
The embedding of metadata in the DNG file is more of a mixed thing, from what I see... Particularly, the data/treatment separation that takes place when using a CR2+XMP sidecar really helps backup : to backup changes made on the treatment/metadata of existing images, you just have to update a few kBs of XMP on one side, vs. a few MBs of DNG on the other.
I'd also think that in the CR2+XMP scheme, you could set the CR2 file read-only to make it safer from bugs (but this idea may only be the result of having been repeated the data/treatment separation paradigm a few too many times).
and the value of the adjusted previews and thumbnails which can again be leveraged in other apps which aren't raw converters, as well as some that are.
The value of updated previews can be a real blessing in some workflows, that really makes no doubt.
And going back to fike's original question...
To me, the debate boils down the the question of what format will be supported longer Canon CR2 or Adobe DNG.
Do you know a good
cybermancer? That would help a lot.
Another reason I was reluctant to make DNG conversion part of my workflow was the loss of Canon proprietary CR2 properties that can only be accessed through Canon DPP.
As far as I've understood the topic, these proprietary metadata are still written in the DNG, so even if you can't access them from the DNG for now, this limitation you might be overcome in the future? See previous line for more details...
