I'm not sure about what SoCu really means. I see a kind of problem with O&A: You open it for some slide, and make 10 modifications. Then you come to the decision to leave the slide as had been before opening O&A (i.e. leaving the slide unchanged). In this situation you cannot close O&A with just one click. You have to click the undo button 10 times.
My opinion on "Autosave every x minutes": A horrible feature. You sometimes make a mistake and some nice work is gone. If then Autosave does what it is meant to do, then you have lost something. I myself prefer my own version management which gives me the opportunity to backtrack the whole development of my project. But: chacun à son goût