For me, the encryption of the backup is essential. I, like most serious techies, have a significant amount of HD space at home. I'm strict about making backups to a networked drive, daily, but never fully put in to place something for off site backups. I have thousands of image files on my NAS and I even go as far as to burn them to DVDs. The DVDs are sitting next to the NAS!
To store something remotely, the backup has to be secure and that means encryption. I don't want everyone working at the remote site being able to poke through my images, financial information or prescriptions. If the encryption is good, it'll be the product for me!
Rob