I continue to use and favor SOS Online Backup. All of my priceless family photos and videos, along with documents important to me, are reviewed weekly by SOS and if there are new files that have been added since last week or files that have been changed, they all get backed up to the SOS servers.
I have been a customer for maybe 5 years now and have never had a problem. Occasionally I will select a file on the SOS servers and download it just to make sure all is well. Having an SOS Online Backup account is like having a safe deposit box for all of my computer files. I hold the key and can go there anytime I wish to doubecheck that everything is as I expect it to be.
I have set up my account to run weekly backups automatically, and the system works like a well-oiled machine. I started out having these auto runs on a daily basis, but as my confidence grew with SOS I have found weekly runs are just fine. Each week I get an e-mail reporting the weekly activity, so I know things are working smoothly.
If you have computer files you would rather not lose, you should be backing them up.
I use and recommend SOS Online Backup.