Bag vs Bagless
There is a huge difference in the vacuum cleaner market between the cheap machines often made in china and eastern countries, compared to the higher grade machines manufactured in Europe and America.
All vacuum machines have filters, in bagged machines the bag is the main filter, in bagless machines the cyclone effect traps the larger dirt particles but a filter, or filters, are needed to trap the smaller particles.
With a cyclone machine the air has a much longer journey in order to by-pass a paper bag, it must work its way round the cyclone and because there is no bag, these machines must have 2, often 3 much thicker filters to protect the motor of any dust missed by the cyclone. This very long air journey and much thicker filters put a lot of stress on the motor reducing its life dramatically also making the machine a lot noisier when in use.
There are a lot of bag-less machines manufactured where the cyclone design is so bad that the filters are doing most of the work stopping the dust going into the motor. This causes two problems, after a very short time using the machine your suction and performance drops significantly. Often bag-less machines work great for the first 2 weeks then a significant drop off in performance is experienced as the filters become chocked up. This then causes the motor to run at a much higher temperature reducing its life dramatically.
Another problem is how hygienically we dispose of the dirt, when you come to emptying a bag-less machine it all rushes out into the bin hitting the bottom and making a huge dust cloud going everywhere. With a bag machine you simply remove the paper bag seal it and throw it away, the dust is always sealed inside the paper bag.