I've used OP sacks for the last 10 years (at least) in the Sierra Nevada backcountry on annual trips. They were used in conjunction with an Ursack as final protection. On at least 4 occasions when bears were IN OUR Group's CAMPSITE the bears failed to detect the food I had; my food was taken by me as a supplement to the group's food. The latter was stored in aluminum panniers ("bear boxes" if you will) used now by all mulepackers in the Sierras. So it might have distracted the bears from detecting my food, since there was no attempt to conceal the contained food's odors, as I did with the OP Sacks. On many other occasions there was no evidence or knowledge of a bear's presence during the night, but we were in areas notorious for bears along the John Muir Trail, such as at or near Thousand Island Lake, Lake Ediza, Glen Aulin, (and ALL other sites on the Yosemite High Sierra Camp Loop), Rock Creek (Cottonwood Pass region), Cottonwood Lakes, Rae Lakes, Paradise Valley and other sites on the Rae Lakes Loop (this included one of the episodes of a bear in camp attacking the aluminum bear boxes but ignoring my stash) or East Lake. Indeed, I've not had my stash moved at all suggesting a bear had tried to get the food but gave up. I might add that my food was always some distance away from the aluminum boxes containing the group's food, which I would think would lessen the "distraction" factor sited above.
So the bears ain't got my food yet.