When you create a .ISO file you are basically just conglomerating the files within a DVD into a single file for easy handling. There is no reencoding of the file involved. The files are untouched. If you want you can reburn the content into a blank DVD and have a perfect copy of your original DVD. Depending on the speed of your DVD drive it takes only a couple of minutes to create a .ISO file from your DVD.
With reencoding you are changing the .vob file on the DVD (mpeg2 format) into something else like .avi (divx format). This takes much longer and you lose your DVD menus. And since you are reencoding there is some loss of quality.
Of course this is not important if you are just downloading your movies and do not have a DVD collection.
Sorry if I was not so clear on my comment. I understand the difference between creating an ISO and VOB.
On the other hand, I was actually referring to the motion of putting your DVD into file, which is generally the same for either ISO and VOB, even though one may take more time to do than the other.
I focused on what you said about not having patience in "doing", because for me the overall process/steps are rather the same in which you take the DVD, run a software on it and extract/create file(s) out of it.
But then, sorry for the confusion. Please just ignore this. Thanks.
BTW, I noticed that VOBs have much sharper image than ISOs on the WDTV.
I don't bother with the menu's and special features anyways.