- Significantly lighter 8oz vs 44oz for 10 liters of space.
- Shrinks as food is eaten.
- Not a large hard object in your backpack.
- Legal to use in more places.
- More bear-resistant, there was a case in Yosemite where the bears were rolling them off a cliff and then the canisters would shatter so they are not 100% bear-proof.
- Keeps the bears from squishing your food which a Ursack won't do without an aluminum liner.
- It is much harder for the bear to take the canister away, unlike the Ursacks.
In my opinion, the Ursacks are easier to take backpacking and the canisters are better for places with a higher likelihood of bear encounters.