Kenmore Progressive - it's been the CR top rated canister for years. Currently there 's a new Kenmore model rated # 1. I forget the name. But I own 2 Progressives and they are great.

I will tell what we bought and can say as far as performance we could not be happier, don't know about longevity yet because we have only owned it for little over 2 months.

We got the Shark Vacuum, model NV356E with the hardwood floor attachment.

Works outstanding, is as good or better than the Dyson in every respect.
When I bought this one I tested it at Bed Bath & Beyond on the DYSON test carpet, I used the Dyson first, ran over the carpet at least twice in every direction then took down the Shark and ran it over the same carpet and it picked up quite a bit more dirt that the Dyson left behind.

The ONLY small fault I have with it is the hose is a wee bit too short and doesn't stretch so makes it slightly difficult to vacuum like way behind something like a PC desk etc where you just want a hose with a very small attachment so that you can get into tiny crevices.
I have ordered an extension hose from another model (NV22) in hopes that it will fit then I will have the perfect vacuum.

It is an upright bag less vac that turns into a light canister in about 2 seconds.
Zero loss of suction, easy to empty, has a small head with roller brush that gets into tight spots easily, goes down almost flat when used as upright to get under furniture pretty well and if that isn't far enough then simply push a button and turn it into a canister with hand held floor brush or small "turbo roller brush" that get under ANYTHING.

Plus we only paid $160 from BB&B using the 20% coupon.

I doubt there is a better vac even for 3X the price.

Check out the reviews on Amazon, between the various models I imagine there are around 1500+ reviews and I bet at least 85+% are 5 star.

For a canister, I have an Electrolux Oxygen with hepa filtration, and it has worked well.

Although you prefer a canister, there is an upright vacuum that is hard to beat and is consistently top-rated: Hoover Tempo. This vacuum has tremendous suction and is nearly indestructible. Plus it's only $70 - $80! I've had one for years and it's great. It also has an allergen filtration system on it.

Both of these are bagged vacuums. I'm not sure what the attraction is to the bagless. Seems to me that every time you empty canister, you spread the dust all over everywhere, so I prefer the bagged vacuums.

groupp;

What your mother has would be a Filter Queen Majestic. Filter Queen is a very good vacuum cleaner. Their filter cones keep alot of the dirt in the container. Sometimes the cones are more expensive, but you have to figure that the vacuum cleaner will hold alot more dirt than the regular vacuum. You might want to look for a used Filter Queen, which is in very good condition.

If you are looking for a canister with power nozzle, and money in no object, you will find many to choose from. Look at Riccar, Simplicity, Miele, to name a few.

If you have a smaller budget, look at Hoover's Windtunnel Anniversary edition bagged canister or a Panasonic. Both will have more options if it needs to be repaired under warranty. The Hoover has a good warranty, very good floor brush and is relatively quiet. The power nozzle does a very good job on carpeting. I do not care so much for the onboard attachments though and would hunt for better attachments to use. TTI also markets this vacuum under the Royal name; with an updated power nozzle. You can find discounted prices for the linked Hoover.

I would only use CR to compare features. I do not like how they rate their tested vacuum cleaners. They do not think someone needs to purchase a higher priced vacuum, if a cheap vacuum will clean. There is more to a vacuum cleaner than its performance.

Here is a link that might be useful: Hoover Windtunnel bagged canister

I'm so much happier with my Miele "Callisto" vacuum. I had a Dyson canister and hated it. The Miele picks up dirt much better, is quieter, and I'd never go back to a bagless vac.

The Dyson was pretty expensive, so I suffered with it as I felt too guilty about throwing it out and perhaps was punishing myself for falling for their advertisements. When the Dyson broke (after only about 2 years), the repair quote I got was so high, it made sense for me to junk it and buy a new vac.

In that sense, I'm honestly grateful that my Dyson was not durable! Go with a Miele if you have the means. As the saying goes, buy the best and you'll cry only once.

We bought a used Simplicity Verve canister on ebay. Looks like new. Suction is outstanding, great power head for area rugs, tools work well. Bare floor tool easily picks up cat litter. HEPA filtration.

CR never rates these well because of the cost, but we have been very happy with Simplicity uprights and canisters for the last 17 years - our Simplicity upright is still going strong and has had only one minor repair in this time. Riccar and Miele users we know are also happy with their vacuums.

I second the Mieli. I got the model S2121
from Amazon, for $299 w/ free shipping.
I've only had it for a couple of months,
but it is GREAT!

I've had my Miele Platinum for 15 years and it still runs like new. We bought it just after my son was diagnosed with Asthma. When we ripped out the 20 year old, nasty carpet in the living room 7 years later, the guys were extremely impressed at the lack of fine dust under it.

Cj