Diff. Backup Script Using TAR. Should be simple.

I'm specifically trying to find help or insight on using the --incremental ('-G') option for creating a tar. Please resist the urge to tell me to use --listed-incremental ('-g') option. That's fairly well documented in the GNU tar manual. GNU tar 1.19

This is what the manual does say in section 5.2:

What I'm trying to do is write a small backup script that will create one tar file that contains all the changes since a level 0 tar dump of the directory I'm backing up. That way, I save time and resources only backing up new changes. Since I have no interest in creating multiple levels of incremental backups, it seems like the --incremental (-G) option is better suited to my task. And it would be nice not to have to hassle with a snapshot file if it's unnecessary.

Also, it appears that using the -N option isn't recommended for incremental/differential backups. From section 6.8 Operating Only on New Files:

Help is much appreciated.
Gabe