my case I set auto-save to every 6 minutes and keep 10 copies. This way at any point in time I have up to a one hour backup of all my work in 6 minute intervals.

This has saved my lots of work in several instances where I have made immutable changes to a complex model and then realized that they cause major problems down the line but I was able to step back through my auto-saves and get back to a point before the offending changes.