A high wattage (input power) doesn't always mean better suction because the amount of this power that's turned into air watts (suction or output power) depends to some extent on the vacuum's design and efficiency.
Bagless vacuum cleaners are by far the most popular choice. Contrary to popular belief however, a bagless vacuum cleaner will not necessarily perform better than a bagged vacuum. A bagged vacuum can also be the best choice if you or anyone in the household is asthmatic or suffers with a dust allergy. Before you buy, knowing the advantages and disadvantages of bag vs bagless vacuum cleaners can ensure you choose a vacuum best for you.
If you suffer with asthma or a dust allergy, the filtration system should be an important factor to determining which vacuum cleaner you'll buy. This is because the filtration system will determine the size and number of dust particles that'll be in the air when it is exhausted out of the vacuum.