So what is the draw or benefit of the efolio? I haven't signed up for it and in reality, not sure I really want to.

Do you still get a paper receipt showing all your charges and payments at check-out? If not, then how do you verify that Marriott hasn't made a mistake of sometype? I wouldn't want to find out that there was a problem with my bill 2 or 3 days after I have checked out. I would want to be right there at the hotel getting it resolved before I check out rather than afterward.