I am a total bagged vacuum fan but there is one thing I've always noticed. When I put a new bag in a vacuum and the clean the carpet really well, and then feel the bag to feel the dust, it seems empty. BUT, when I vacuum with a bagless vacuum, it fills up with dust very quickly. Although I have had experiences when a vacuum bag becomes full within days (A Hoover model #704), why does the bagless vacuums fill more quickly?! I mean I've vacuumed my whole house with a bagless and had to empty to 4 times! Does the bagless "fluff" up the dirt and make it look like a ton, or is there something about the system that really makes it clean better? I always thought this was weird...