I convert everything to DNG format and put it on double layer DVD's after deleting the useless ones.
The purpose of editing is to improve an image in some way. By definition of the purpose of editing, the original will always be 'worse' than the original some sense, won't it?
Think about it.
Why keep the originals if the edit is better? There are several reasons, not the least of which is that there may be a different treatment of the image and you will want to start from a good original and work to the new treatment. Or, and this is a big one, the edit you thought was so great isn't so great after a couple of days of looking at it. I also keep original images because I may use parts of one in another and I find that it is easier to integrate the material when I am working from an original.
Vance
Vance