HEPA filter stands for “High Efficiency Particulate air filter”. This filter is for filtering out particles contained in an airstream, at high efficiencies.
No, not necessarily. The wattage of a Vacuum Cleaner’s motor measures electrical current, not performance or suction power. The performance of the Vacuum Cleaner depends on the overall design, the filtration, and the air flow.
Using disposable or reusable bags in a Vacuum Cleaner is always recommended. When you place a new bag in a Vacuum Cleaner you are putting in a fresh clean filter that immediately brings the vacuums efficiency back up to its optimum level. Using a vacuum without bags can also be very messy and can block up filters that are hard to clean. A Vacuum Cleaner without bags also tends to develop a smell in the filters that is almost impossible to get rid of without replacing them.
Airflow is what actually does the job when you are vacuuming. Airflow is all about the speed or air moving from the floor tool up the tubes down the hose into the bag through the filter, through the motor and out the side of the machine. If any of these areas have a blockage or restriction then the speed of air will slow, thus creating poor cleaning performance. Airflow is also essential for sufficient cooling of the motor whilst it is running. Poor airflow can result in overheating and eventual failure.
This really comes down to personal preference, some people like the combi nozzle for its weight and usability, other people that are moving between hard floor and carpet a lot like a freeflo nozzle or a wheeled brush foot. Sometimes you might even find one floor tool is better for different types of carpet.
It’s always good when demonstrating a Vacuum Cleaner to have several tools handy, sometimes people might not like a vacuum because it doesn’t feel right to them, it is probably only the floor tool so you can swap it for another and get them to try it again.