I have just seen good explanation of the different ways Transcoding is handled (DVD2One forum)
VARIABLE recommended for full-disk backups, Because it's designed to donate more quality space to the main movie, and squash the hell out of the rest of the disk.
CONSTANT for movie only? Because you'll want the best quality for that one track, and DVD2One relies on the wisdom of the original encoding rates to determine how much to compress each frame.
and it made me wonder if CloneDVD handles the Transcoding similarly, or does it always use Constant bitrate?