It may be that Europe is the birthplace of the canister / cylinder vacuum and they have been much more focused on improving the features related to suction and airflow compared to North America. One of the main differences in canister design between the two sides of the ocean is the variable speed motor. It has always been far more common in Europe to see canister vacuums offering variable speed motors which use an onboard voltage transformer to adjust from the maximum 240 volts down to more gentle settings. You will often see the adjuster labelled by wattage for the settings on these European canisters: 1400 watts, 1000 watts, 600 watts, etc.
In comparison, North American canisters have rarely offered "Electronic Speed Control" - and often only on the deluxe top-of-the-line models. Our canisters more often offer mechanical suction relief valves to adjust suction. So it's easier to just show the single amperage of the motor (12 amps, etc). Before the 1980's, our canister vacs were rated by horsepower - with 3 or 4 HP being quite powerful. Can't remember how horsepower ratings are derived, though.
