Many manufacturer's develop their packaging to keep their foods as fresh as possible. They often recommend, not to pour the food into a plastic container directly, but instead, place the entire bag in the plastic container. The air-tight container will keep the bugs out and keep the food fresher.
The benefits of putting the bag in the container.
I personally, like the plastic containers on wheels, it makes it easy to move around and their large enough to leave a food scoop in it! Iris makes some the best plastic containers. The 45QT ones hold up to 40 lbs of food and fits a 30-33 lb bag of food in it's original packaging comfortably.