This is a great alternative
This is a great alternative for our soda making machine that we ran across by accident. Before "Corona-times" our supply of fresh CO2 was retail. Now, it's a much simplified process of dropping the empties in the mail and having them arrive a little less than a week later in most cases.
Just about $4 more per C02 canister, but worth the convenience (in addition to which the manufacturer of our machine is chronically out of stock and has poor service). The convenience more than balances out the cost.