As long as you have an image there really isn't a need to ever take another unless you do something like add an option. If you need to do a restore you can just put in an old image and then immediately put an AOTA to get up to date programs.
While there might not be a need to take another image unless you add an option or change a system variable, what would you rather load: an image from this year, or one taken 5 years ago?
I take an image backup and a copy backup at the beginning of each year, cheap insurance is the way I look at it.