Single-copy template and shared mail

With disk costs being as dirt cheap as they are, does anyone feel the need to use the single-copy template or shared mail features these days? I can see where they made sense years ago when drives were smaller and more expensive, but having single points of failure is a very risky proposition and doesn't seem to be justifiable today. If you are very concerned about disk space, quotas and archiving policies are the way to go. I'd like to hear about some current success stories to balance my thinking on this. Right now I just can't think of a scenario where I'd recommend their implementation.