Hoover invented a Bag in the forties and why we keep trying to re-invent the wheel is beyond me.
Bagless vacuums are not truly bagless. WHAT DID HE SAY?
Think about it something must keep the dust from entering back into your air, what is it?
A FILTER! Imagine running your vacuum with a dirty bag all the time, that's what bagless vacuums do. As soon as you use the vacuum the filter becomes dirty, and that filters only job in life is to capture dirt and not let go of it. Trying to clean them is a joke and eventually your motor will become so starved of cooling air that it will quit.
Bagless vacuums usually start out with pretty decent airflow, but after one use, I have measured drop offs of up to 80% in power. Once the vacuum has been used the dusty filter will prevent the vacuum from ever being at 100% efficiency ever again.
Think about this a vacuum company makes about .80 on a package of bags you buy twice a year or so.
They make at least $5.00-$10.00 on each filter you change. You tell me what they are going to market.
Bagged uprights with allergen bags will clean better and last longer plus you wont get a dust bath everytime you use them.