I used to sell sweepers at Sears.
Please keep in mind that I don't work there any more and I have NO stake in the company sales or anything.

Panasonic and Kenmore are both good sweepers, actually when I worked there Panasonic made Kenmore sweepers.
Whatever kind you get make sure to read the fine print. If you buy a Hoover, it might say "19.5 amps per ....." but that doesn't mean it is the best. The highest you can go is 12 amps. period
My mom has had an Electrolux as long as I can remember so it is at least 27 years old.
She also has a Hoover Windtunnel Upright and a Kenmore canister. Compliments of when I worked at Sears!
I have a bagless. It is the Kenmore Destiny a replica of the Fantom.
I like it alot but the next one I buy probably will have bags.
Any questions I can try to answer best to my ability.