Watts are an input, not an outcome
Of these five machines, two publish a number that describes air moving rather than electricity arriving. An archived retailer specification page lists 158 CFM for the Complete C3 Cat & Dog. Dyson gives up to 290 air watts for the Ball Animal 3, in the highest of three selectable suction modes. Those are not two readings of the same quantity — cubic feet per minute and air watts are different units — so even the two best-documented machines in this set cannot be ranked directly against each other on airflow.
The other three publish wattage or nothing. Shark’s CZ351 canister lists 850W, with no airflow figure in any retailer listing retrieved for this model. The ZU503AMZ upright’s manual lists 120V~60Hz and 1200W, and no airflow figure appears there either. A retailer listing gives 183W of suction at the hose end from the 81615’s two-motor system, next to a 120V/12A rating that arithmetically implies roughly 1440W drawn at the wall — two measurements taken at different points in the machine, which is why they cannot be reconciled into a single figure.
For a household weighting airflow heavily, that distribution is the finding. Three of the five give you nothing to check.
“HEPA” and “sealed” are two separate claims
The ZU503AMZ upright has a comparable stack — foam and felt pre-motor filters plus a separate HEPA filter, marketed as part of an Anti-Allergen sealed system — and, alone in this set, a published maintenance schedule: rinse the HEPA filter yearly and replace it every three years; clean the foam and felt filters every three months and replace them every two and a half years. Those intervals are an ongoing commitment in time and parts that the other four machines do not document.
If a HEPA designation is specifically what you want from Miele, the Cat & Dog is the C3 that does not carry it.
Which body style your floors argue for
Weight is where the upright-versus-canister question stops being abstract. Miele’s main unit is 11.8 lb, and on a canister that unit is dragged behind you while the wand and floorhead do the carrying. Kenmore’s 81615 is the heaviest body here, nearly double Miele’s.
The Dyson is an upright, so its figure is what you lift as one piece onto a stair, and its 42.2 in height, 15.5 in length and 11.02 in width are what you steer around furniture. The ZU503AMZ publishes no weight at all.
The brush that keeps spinning
One document in this set is candid about what a floor switch actually does. The ZU503AMZ’s manual describes a Power/Surface switch with Off, Hard Floor and Carpet positions plus an independent MIN/MAX suction slider on the handle — and notes the brushroll spins in both floor positions, so the switch primarily changes suction level rather than disengaging the brush. The same manual names the setting for deep-carpet cleaning per ASTM F608: suction at MAX, floor switch on Carpet.
Dyson takes the opposite approach and states it plainly. One de-tangling Motorbar cleaner head is stated as suitable for all floors, with no separate hard-floor setting and no swap-on bare-floor attachment in its specifications. If your objection to uprights is a powered brush running over hardwood, the Ball Animal 3 does not answer it.
The two bagged canisters do, by changing hardware rather than flipping a switch. Miele’s included bare-floor head is the SBB300-3 parquet brush, with the motorized SEB228 Electro Plus powerhead for carpet. Neither has a brush on/off control; both let you put a head with no motor on the floor. The cost is that the change happens every time the flooring does.
For the CZ351, nothing about floor-type switching is published in any source checked — on a mixed-flooring decision, that is the gap that matters most.
Bags, bins, and how often you open the machine
A pet household fills a container faster, which turns capacity and the manner of emptying into a decision rather than a footnote. Miele’s bagged C3 holds 4.76 qt (4.5 L) in a Type G/N AirClean bag, more than twice the published capacity of anything else here. Kenmore’s bag holds 2 L. Dyson’s 0.45 gal bagless bin and the CZ351’s dust cup, published inconsistently at roughly 0.475 to 0.5 gal depending on the retailer, are the two smallest here and are not separable given that disagreement. The ZU503AMZ’s manual states no capacity, only that the self-cleaning brushroll sends wrapped hair to a dust cup.
The bagged-versus-bagless split outlasts the numbers. A bag is sealed when you take it out; a bin is open to the room while you tip it. Dyson’s filters are washable, the CZ351’s HEPA filter is washable, and the ZU503AMZ’s manual has you rinse its HEPA filter yearly rather than buy a new one. Miele and Kenmore both run on bags you keep buying.
When the less-documented machine is still enough
Thin documentation is not the same as a weak machine, and it is worth being precise about what it costs you. The ZU503AMZ’s manual states what the floor switch, the filter schedule and the warranty actually consist of: five years limited, explicitly excluding wearable parts such as foam filters, HEPA filters and pads. If your decision rests on floor-type control and knowing what maintenance you have signed up for, that machine is well documented on the axes you care about and silent on the ones you do not.
Reach, and what one outlet covers
All five of these are corded, so cleaning radius is fixed at purchase. Dyson states 50 ft of total cleaning reach combining cord and hose stretch, with a retailer separately listing the cord itself at roughly 35 ft — the largest published total here. Kenmore’s 28 ft retractable cord plus 10 ft of additional hose reach comes to 38 ft. Miele’s cord is 24 ft with auto-rewind, and other retailers cite a roughly 33 to 36 ft operating radius for similar C3 SKUs. The CZ351 has a 25 ft cord. The ZU503AMZ publishes no cord length. Path width is thinner evidence still: Kenmore’s 14 in and the CZ351’s 10.2 in are the only two figures published, so how many passes a room takes is unknowable for the other three.
What a blank cell tells you
The comparison table leaves cells empty where no retrieved source states a value, and that is information rather than a formatting choice. A buyer cannot verify an unpublished figure before purchase, so a blank tells you the manufacturer did not put the number anywhere you can check it. On this set the blanks cluster: three machines publish no airflow, one publishes no weight, capacity or cord length, and one publishes nothing about floor-type switching. They cluster on exactly the two factors a pet household with mixed flooring should weight most heavily, which makes this choice largely a question of which gaps you are willing to accept.
