I stay away from autosave, think about how easy control+s is.
just press control+s every 5 minutes or so and make sure your saving during times where not much is going on because
let me ask you this.
would you save a project while you were in the middle of inserting a soft synth ?
I wouldn't do those 2 things at the same time because one is cpu intensive, the other is trying to gather the info to save to hard disk.
this can lead to white screens. not always, but sometimes and im not about to take that chance.
as some have learned even saving a project while the transport is in motion can lead to a white screen.
you can use it like grem is saying but I find it try's to save before the cpu is done slowing down from a move that may be intensive.
just my opinion
good luck