I think nobody should be willing to take risks when it comes to managing data. External storage devices can also go kaput ay any time and data stored in them can be lost forever.
Backing up critical data to an online storage service like IBackup is an intelligent step because even if PC crashes the data will there for recovery in the remote online server.

Besides scheduling backups at a time of your convenience, IBackup allows you to manage all the backups you have scheduled with IBackup for Windows and check whether everything is all right.

I’ve been using Streamload for some time and it is primarily for storing medias files. For storing critical data, I prefer IBackup because it looks like a service that you can always bank on.