I have all of mine. I would advise one to hold on to them. I also use them when I install on a new machine I may need to install the various plugins that no longer ship with Sonar.
You gain nothing from discarding them and you may need them in the future.
"From Greg Graves CAVEAT: Any saved thing will sit there, year after year collecting dust, tempting you again and again to get rid of the damn thing ... and when you finally give in and toss it ... you'll immediately find you need it." I think its a law of the universe. Right up there with "what can go wrong will go wrong".