
SEBO
AIRBELT E3 Premium
Ultra-durable, 10-year warranty, but expensive with short cord.

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The D4 is the big daddy. The E is the newer design but smaller and convenient for most people. The K1 is the oldest design and a little bit quirkier. The D is probably the best engineered, but unless you need the long cord and the giant bag, the E1 is probably better for most people. The analog slider for suction power on the e1 is the better design. They all use the same motor with 2000hr service life and have the same suction. The k1 allows you to attach a Hepa exhaust filter I believe. There is no appreciable difference between Sebo s class and Hepa (unless you happen to be an electron microscope). The white color is best at hiding scratches. You're buying a Sebo for effectiveness, reliability, repairability and cheap consumables (relative to Miele). They are engineered to just work for decades. The Miele's tend to require maintenance.
A Sebo or Miele canister with a simple suction head. You don't really need a power head unless you have carpet. Sebo: K1 and E1. Miele: C1 PureSuction.
Sebo K1 or K2 would fit your needs and be in your price range. They have a 10 year motor and parts, 7 year labor warranty if you buy from an authorized dealer.
You might want to know, the Sebo K series is designed for smaller homes, it takes a smaller dust bag than the rest of Sebo's line. Not that this should discourage you from getting a K, just to be aware of this. Their E and D lines are what they offer for bigger homes. As a Dyson V11 Outsize owner, I think that Dysons are overpriced, and their build quality is not great for the money. They tend to run on lower suction so as to conserve the battery. Turn up the power level and the battery drains faster. And the dust bin gets and stays dirty as do the inner air passages, I'm always banging the side with the bin open to get the finer stuff out. I bought that Dyson and A Miele Marin within a few months of each other. The Miele suction is far superior and it's quieter than the Dyson. I use the Parquet tool for our bare floors and it will suck up anything with no problem. However, the stick vacuums feel easier to work with. But I've found I prefer the cleaning performance of the Miele and the easier dust bag removal is great. You can't go wrong with either Sebo or Miele if you decide to opt for corded vacuums.
We also have a Sebo K series that the man in the specialty vacuum store said it was the only vacuum he would sell us when I told him we have a husky. Our cleaner (she has been working for decades) told us Sebo is the best vacuum you can get. It never breaks but if it does it is repairable.
while it is far too early to determine longevity of Miele's latest models but anecdotal evidence shows that the new motors in the latest gen of Miele vacuums are not nearly as robust as the C3 series it replaced. Sebo as far as I am aware, has more responsibly priced repair parts and they haven't made any noticeable engineering changes to their designs. WRT to the K series vacuums, they're a nice well priced unit that packs a punch as far as performance goes but I would say the 1 thing that drives me a LITTLE crazy about the canister is the offset hose inlet. Not really deal breaker though b/c you put the canister in the middle of the room and then vacuum "outwards" so you're not rolling it around much.

SEBO
AIRBELT E3 Premium
Ultra-durable, 10-year warranty, but expensive with short cord.

Numatic International
Henry Canister Series
Budget king, super durable, but heavy and poor on carpets.

SEBO
AIRBELT D4 Premium
Durable, powerful, long cord, but heavy and pricey.

SEBO
FELIX Premium
Durable, powerful, good for allergies, but heavy with awkward attachments.

Miele
Classic C1 Cat & Dog PowerLine
Durable, powerful, quiet, but very expensive, short cord.

Ranked #1
SEBO - AIRBELT E3 Premium

Ranked #1
SEBO - AIRBELT E3 Premium

Ranked #1
SEBO - AIRBELT E3 Premium

Ranked #1
SEBO - AIRBELT E3 Premium

Ranked #1
Numatic International - Henry Canister Series

Ranked #1
Dyson - V15 Detect Series