I've used an UrSack lined with an Opsack full of food in Ziploc freezer bags, and haven't had an encounter... yet. But I think it's important to think about just where you're hiking, what time of year it is, what the weather's been like, etc., before you make up your mind.
I've had success when I've hiked in/around Colorado's Front Range, in the middle of the summer. In that region, at that time of year, all kinds of tourists are in town. The bears tend to trek down to the many established campgrounds, small mountain towns, and cottages-- where there are lots of trash bins, bird feeders, roadkill carcasses, and carelessly stored foods (my favorite: someone left a bunch of half-full beer bottles on the picnic table outside their RV, and was awakened in the night by a bear tipping over the bottles and licking the table clean). Berries are starting to ripen then, too. So, going higher in the range, away from those places, has helped me avoid the bears (or so I think).
Plus, I've found it very difficult to hang my food effectively when all the trees I see are 10-12 ft subalpine firs. So it made sense to me to choose tying an UrSack as high on a tree as I can.
When I head out in Fall, and the bears are going ballistic looking to eat anything and everything in prep for hibernation, I use my bear canister.