heehee.... the major 'biggie functional advantage' of the Stretch-Tite dispenser is keeping the 'last cut edge' of the stretch film available to grab.
it has two flapper jaws the film passes thru, when the film is cut, those two flapper jaws keep the film from 'retracting / disappearing' so at the next use one does not need to rethread, refind edges, etc etc.
I outlined the 'notches' with black marker - here's my left hand pull, right hand camera shot....