Great, I know for sure that this friend of mine who works for the feds is reading all this. But just in case he doesn't here are the results of my backup DVDs.

I backup my very best movies on Dual Layer DVDs which I obtained for the price of $2.50 each. It was a one time sale at OfficeMax and I haven't seen them since. Anyway so I grabbed 20 and have used five of those until now.

The dual layer backups are as brilliant as the originals in terms of audio and video reproduction.
Single layer discs work great but it depends upon the orignal movie size also. If the original movie is more than 130 minutes then the picture starts breaking at times because it is severely compressed. Sound remains pretty faithful though.