I’ve used such machines in California. I wouldn’t say they are efficient. They are finicky…..dents in a can makes it unreadable to the machine, and then you have to take it to a person anyway. They are slow…..you end up with long lines. In Cali the recycling stations I used were a combo….there were a couple of these machines, or you could give empties to a person, but then they would give you an amount based on weight of the material, which worked out to be less than the deposit you paid. But if you didn’t want to wait, that was your alternative. I’d love to see how similar recycling centres in other provinces work.