Not exactly sure. v14 doesn't have support for Dual Layer Disc loading where as 15 does. But others say that v15 has some bugs in it that 14 didn't and they also say that 14 was much more stable. If you are only going to be using a USB loader, stay with v14. If you're going to be loading backups from DVD-r, go with 15 or 16. I've tried all 3 and never had a problem. I am currently running v16