I do all my backing up with DVD Shrink. The first time might take 2-2 1/2 hours at my settings. Backing up that resulting copy might take only 1 hour after encoding and burning. Is there any way around encoding every time and just burn exact copies that will turn out just as high quality? Hope my question makes sense. If not, just let me know and will try rephrase.
Create an ISO image with DVD Shrink and you can burn that image as many times as you like with DVD Decrypter or Imgburn.