They are not really the same thing. An image can't be booted from. I really want to know that this OS & data are safe and don't trust a container file from some software I've not used before. A clone allows me to actually boot up on the IDE and verify the OS etc are what they should be before committing changes to the boot parition on the production array if you will.
Mr. Murphy is in the room with me... I don't need him screwing this up. :-\