Agree it is hard to scientifically justify without very large studies on exact hit locations and lethality of the more-peripheral-but-still-torso hits, but for me personally it helped me wear the armor more because it is more comfortable (esp as I have a long term shoulder injury) and the extra maneuverability means I can do all tasks with armor on, never need to strip it off. Wearing armor more is always good; zero chance of ballistic protection when it's laying against a tree over there.
I tend to say it also lets me shoot better. Not necessarily because the butt is more on me than plate, but because I can get in positions more naturally, e.g shoot from prone pretty much properly whereas more full coverage plates (esp ICW!) can get you feeling pretty Michelin Man.