If the upright vacuums are cordless (or corded), as well as suction and motor information.
Cleaning characteristics for each upright vacuum cleaner including its filter, cyclonic action and if it is rated for use in homes with pets.
Compare the nozzles, cleaning heads, brushes and other accessories are included with each upright vacuum.
The surfaces each vacuum cleaner is capable of cleaning.
The manufacturer warranty and certifications for each vacuum.