This is kind a spin off or different take from "My data is "in the cloud..." What happens when I need it back?"

Best practice to me means regularly testing the restore operation.  if this isn't done how can you know

(a) that it works

(b) that you've actually gotten everything you need on the backup.  (data on desktops etc)

The cloud suggestion is particularly valid, and one reason why we've always kept backups "local" and not across the pacific in US datacenters where most Cloud backup vendors store the data.  But that argument of what happens when I want it back doesn't just apply to cloud, but to any form of backup.

How long does it take to restore the mission critical exchange server?  Is that time acceptable?  Whats it worth to you to restore faster?

Just one of the questions that need to be asked with any backup process.