I have a little camp stove that uses the same butane/propane mix canisters as the OP. When unscrewed from the stove the hole automatically reseals so you can store the canister for the next use. However, with some brands of canisters I did notice a little gas leakage when either screwing or unscrewing from the stove so it's good to do this as quickly as possible. Main drawback is the cost of the canisters and the amount of waste from the empties. For longer trips I use a white gas stove, but the canister one is convenient for shorter ones - the one I have comes in a little orange plastic box, includes piezo-electric spark lighter, weighs 4 oz., and cost $7 from Amazon.