I always keep my originals - wouldn't dream of getting rid of them. You never know when new advances in "processing" technology will come along and you will say - "I know just the image I could use that on!" - take for example the recent introduction of "Content Aware Fill" in Photoshop. If you delete them, then you have lost that "original" record" - maybe that is not important to you, but it is sure important to me.