Re Tank vs canister..
Tank was the term used to begin with when Electrolux introduced their first cleaner sold here in 1924, when the Rexair and Filter Queen came along they were called ,"pot" cleaners, canisters really took off in the 50s.I refer to any cleaner with a hose as either tank or canister...tank if it is a cylinder, which is what most of them are called in Europe, and any box or round shaped machine a tank, Electolux used to say they made only tank cleaners,in some of there old newsletters they showed prototype canisters, which they called canisters...I guess im just old fashioned..LOL!