I like the bagged cleaners best, they are not near as messy to clean when full.
It depends on what you want in a vacuum cleaner. Bagged cleaners are usually easy to empty, don't need internal cleaning, and bags are fairly inexpensive. However, the dust that collects in a bagged cleaner begins to block the airflow, resulting in lower efficiency as the bag fills. Bagless cleaners have a compartment that can collect debris that sticks to the sides over time, needing the occasional extra maintenance. Also, bagless cleaners usually contain an air filter that must be replaced occasionally. However, if regularly cleaned, the filter can last for quite some time, and it's more efficient in the long run. To nutshell: Bagged cleaners are good for quick and cheap. Bagless cleaners tend to be more powerful and efficient over a long lifetime.
I recently moved to a house that has hardwood floors with area rugs from a fully carpeted house. When my windtunnel stopped working I bought a canister vac with a container I empty when it gets full. I have 1 dog 2 cats so I dump it 2-3 times before I am done vacuming the whole house some furniture. The suction power is lacking alot compared to the bags. I really prefer the bags(in hind sight)
Bagless vacuums make a mess when being emptied. Some may actually pick up better, but unless you empty the vacuum outside you are just redistributing the dust back into the house.
Some bagless vacuum cleaners are better than some bagged cleaners yes, but that really applies to which brand you pick.
