I use DVD Decrypter inISO mode for 2 main reasons:
1.) If you want an EXACT copy of a DVD as you stated, ISO mode read & write is pretty much fullproof.
2.) If you copy a dual-layer DVD, ISO mode copies everything-including the layer swapover data. My 1st dual-layer copy was done in file mode and it played perfectly in my DVD player UNTIL it reached the mioddle of the movie. At that point it locked up. The only way to get the movie to continue was to skip to the next chapter. That 's just not right. Since then, I ONLY use ISO mode-unless you want to record just the movie to conserve space. If the movie itself is under 4.7 gigs, you can fit it onto a single-layer DVD, which can save you money.
In this case, load the source DVD in DVD Decrypter, select FILE mode, then select edit button @ top & select main movie files. If this is 4.7 gigs or less, you’re in business.
Also, if you want to save each chapter on a DVD as it’s own .VOB file in file mode-in case you want to burn only some chapters-go to tools, settings, IFO mode tab, click on file splitting on options on left side, and change it to “by chapter”, then click ok. If you have a 22-chapter movie, you’ll wind up with a folder with 22 corresponding .VOB files.
Hope this helps…