Being a Ghost user myself, I'd have to say that if you have 15 gigs of 'stuff' on your OS drive, you need to do some serious house cleaning. That's BLOAT!
I can still get my Ghost backup of C: on a single DVD with FULL compression, and do it in only about a half hour.
That is, after doing a very thorough house cleaning on C:.
When you are using Ghost to backup to an external drive, you are probably using one of Ghost's compression modes. That does slow down the process some.
Doing a Disk to Disk (clone) is the fastest.
The only thing you didn't mention is how you are going to do a restore to a new hard drive when your old one has shot craps. ????
From where will you run the Restore program?
Any GOOD backup routine should NEVER include a backup program that has to be run from the HD. To be useful it should be on a bootable Floppy Disk, CD or Flash Drive. (or, whatever will work on your PC)
My all time favorite, is Ghost 2003 run from a boot floppy. It will put itself on a DVD along with the Ghost Image, thus making that DVD a stand-alone Restore Disk.
I was amazed, one day, to find that Toshiba uses this same technique for their Factory Restore DVD.
Thanks for the info.
The Doctor
General