This is a "Need to Have".
When building Documents, Contracts, Workflows, Funnels, Emails, etc. with multiple elements it's easy to get totally absorbed in the build, with up to an hour going by without saving. Frustrated is an understatement when just a slip of a finger only to realize you have to start all over again.
This isn't just for documents it's any area that requires a significant amount of focus, build time and repeated saving.
I've read through the posts and there are a lot of customers requesting "autosave".
Just do it!