I have been fixing and selling vacuums for 15 years and i think that bag less vacuums are a scam put out by the vacuum companies to make a lot more money.  Almost all bag less vacuums have some sort of  filter that will need to be cleaned regularly which is a total mess and unless you use a brush or compressor to clean your the filter  you will loose a majority of your suction. Also for allergy sufferers a bag less vacuum leaks so much dirt and dust that no matter where the hepa filter or how well you clean it, it isn't doing you any good at all ( I cant stress enough how bad bag less vacuums are for people with allergy's). Plus most of the filters MUST be replaced on a yearly basis and can cost up to fifty dollars! Paper or even synthetic bags are cheaper and usually keep a much better seal inside the vacuum so they act as a much better filter. Do not believe any t.v. commercial most of the things they say are lies or a gimmick. Try going into a vacuum or appliance repair shop and ask the oldest person there what they think.