Dvd shrink can take longer to re-rip a backup. Dvd shrink is a resource hog,especially in the analyzing/encoding steps. She will use 95% of your processor. Someone with an older machine,it would take longer than the ImgBurn route than it would with a faster machine.
ImgBurn,just like dvd decryper,is less of a resource hog. Older machines like my 498 mhz P3 can rip backup in under 5 min with imgburn. My main machine takes longer than my old machine-go figure?
If you got a lot of errors on your backups,dvd shrink can have a harder time getting through them. Imgburn is more aggessive.
Fastest way: Dual drives,do it on the fly with nero/sonic/or any other disc copy program. It's also a good way to test and see how good your backups are.
If those backups were burned on crap media,crap burner,too fast,paper/sticker labels,scratched/damaged-then you may get a CRC error.
Avoid the CRC error and you should be able to make another copy of it. Get the crc error,then good luck on trying to rip it.