Why does the US Assistent have 600watt and the European 1500watt?

The reason for the wattage difference is because of the different voltages used in Europe and the USA. However, the strenght of the machine is no different. Even on the fastest speed the european machine does not turn any faster than in the US. The Ankarsrum is NOT a gear powered motor and has very few moving parts on the inside. This makes it amazingly efficient. It has a belt driven, worm gear transmission which is an amazing design. And unlike your vacuum that has a belt, the Ankarsrum belt does not have anything putting tension on it so it will not wear out or burn up like on your vacuum cleaner.