People ask why pay so much for this program? Well, it works and has continued to do so for five years. The developer has always gotten back to me within hours, usually within minutes, when I've had an issue; one time he developed a "mini-fix" on the fly for me that allowed me to keep going rather than make me wait for the general release update.
Also the program is under constant development and is continually improved. The speed of file transfers has gotten much much faster in recent months, the interface has been totally redesigned, and when new versions of iTunes or OS X are released that "break" the older version of iPod.iTunes an update is usually available within 48 hours.
I use a $24.95 program on the Windows side to do the same tasks; imagine my dismay after buying the new Nano to find that this (Windows) program knew nothing about duplicates and I had to spend time going through my music library deleting dupes one at a time. That's not a problem with iPod.iTunes which while eliminating duplicates is smart enough to know that a song at 192kbps is NOT the same as the same song at 224kbps, and that you might want both.
I've tried a lot of the cheap and free iPod transfer programs over the years but have found nothing that offers anything close to the power, flexibility, and support of iPod.iTunes - sometimes you really DO get what you pay for.