Rip & Burn methods, and .ISO files

I'm a newbie and would appreciate your patience and a few pointers to
straighten me out re .ISO files. My main interest is copying DVD movies in
my collection to DVDRs for backup.

I've figured out how to use RipIt4Me to copy a DVD movie to hard drive,
which produces a Video_TS folder with BUP IFO VOB files, the same as DVDFab
Decrypter. Those are alternate routes to the same thing. DVDFab Decrypter
has always worked for me so far, and it's easiest to understand and use, but
it's nice to have an alternate route available. I've seen 2-3 other methods
involving commercial software but I prefer to use freeware.

Now enters DVD Shrink, if needed, which can re-author and/or compress the
DVD9 disc files to fit onto one DVD5 disc. If DVD Shrink is used, it
re-encodes the movie under a different folder (NAME_WS), still as a Video_TS
folder with BUP IFO VOB files.

If I understand correctly, the contents of any of these Video_TS folders
containing BUP IFO VOB files can be written directly to a DVDR with Nero6 at
any time. At least that has always worked OK for me, so far, and it's the
easiest method for me to understand. But I've seen some mentions that Nero6
won't always work (when & why?).

RipIt4Me help "highly recommends" use of ImgBurn to burn the final video
DVD. However ImgBurn will only burn an .ISO file, not a Video_TS folder with
BUP IFO VOB files. I've seen comments to the contrary, but they seem to be
untrue (...else, please point me towards the required instructions.) It
appears to be necessary to use the "Build" mode in ImgBurn to convert the
Video_TS folder with BUP IFO VOB files into an .ISO file. Then the .ISO file
can be burned to disk with ImgBurn, which converts it back into a Video_TS
folder with BUP IFO VOB files. That just seems like going in circles, and a
lot of Mickey Mouse to me. Why won't RipIt4Me burn the video files to a DVD
directly without going through an .ISO file intermediate stage? In other
words, what's the purpose or advantage of an .ISO file (if any)?

Thanks.

def456