Read some of the differences between DC17 Animal and DC33 Multi Floor below.
In this post, DC17 refers to DC17 Animal, DC33 refers to DC33 Multi Floor.
Dyson DC17 vs DC33
images from manufacturer

Brushbar Control Type
The brush control button of DC17 is located next to the ON/OFF switch, so you do not have to bend down to control; whereas the brushbar control of DC33 is on the cleaner head thus you have to bend down to turn it on/off.

Suction Power
DC17 has a suction power of 220 air watts while DC33 has 240 air watts.

Tools
DC17 comes with a mini turbine head, carpet care kit, and low reach floor tool, whereas DC33 comes with combination accessory tool and stair tool.

Price
DC17 Animal is priced at $549.99 while DC33 is priced at $399.99 at Dyson.com. (prices checked on August 7, 2011)

Bin Capacity
DC17 has a bin capacity of 0.625 gallons while DC33 has a 0.61 gallon bin.

Weight
DC33 is lighter than DC17.
DC17 weighs 20.79 pounds while DC33 weighs 17.6 pounds.

These two Dyson Animal vacuum cleaners are designed for pet hair cleanup, they seem similar, you can read the comparison below and get some of the differences between DC17 and DC28 Animal.

Dyson DC17 Animal versus DC28 Animal
images from manufacturer

Tools
DC17 comes with a mini turbine head, carpet care kit, and low reach floor tool, whereas DC28 comes with a mini turbine head, Flat Out head, combination accessory tool, stair tool.

Suction Power
DC17 has a suction power of 220 air watts while DC28 has 245 air watts.

Pet Hair Cleanup
Some customers said that DC17 does a better job picking up pet hair from carpets.

Airmuscle Technology
DC28 features Airmuscle technology which is useful for cleaning every floor type where DC17 doesn’t.

Price
DC28 Animal is priced at $599.99 while DC17 is priced at $549.99 at Dyson.com. (prices checked on August 7, 2011)

Noise Level
The noise level of DC28 is a bit lower than the DC17.

Clog Problem
DC17 seems easier to get cloged due to its small holes around the cylinder.

Bin Capacity
DC17 has a bin capacity of 0.625 gallons while DC28 has a 0.61 gallon bin.

Weight
DC17 weighs 20.79 pounds while DC28 weighs 20.61 pounds.

Cord Length
DC17 has a cord length of 35 feet while DC28 has a 35.2 ft cord.

Below are some of the differences between dyson DC14 and DC24 Multi Floor:
Dyson DC14 Multi Floor versus DC24 Multi Floor
images from manufacturer

Cord Length:
DC14 has a much longer cord.
The cord length of DC14 is 35.4 feet while DC24 has a cord length of only 20 feet.

Bin Capacity:
DC14 has a much bigger bin.
The bin capacity of DC14 is 0.71 gallons while DC24 has a bin capacity of only 0.19 gallons. Therefore, you have to empty DC24 more often.

Motor:
DC14 has a 12 amp motor while DC24 has a 6.5 amp motor. More amps means more power.

Suction Power:
DC14 has a suction power of 250 air watts while DC24 has only 115 air watts.

Weight:
DC24 is lighter.
DC24 weighs 11.65 lbs while DC14 weighs 18.56 lbs.

Size:
DC24 is smaller.
The dimensions of DC24 is 29.6″ x 11.0″ x 13.7″(HxWxD) while the dimensions of DC14 is 44.86″ x 14″ x 13.38″(HxWxD).

Removing Blockage from Brush Bar:
It is more difficult to remove blockage from the brush bar of DC14.
For DC24, you can just remove the brush bar to clear the blockage; but the brush bar of DC14 is not removable, it takes more work to unblock the beater bar.

Wand:
The wand of DC14 is longer than the DC24.

Movement Type:
DC14 use fixed wheel while DC24 features Ball technology.

Tools:
DC14 comes with a brush tool, a stair tool and a crevice tool; DC24 comes with a combination accessory tool.

Overall, if you have a large house, then the DC14 which has much more powerful suction, longer cord, and larger bin is better; if you have a small apartment, then go for DC24.

Learn some of the differences between dyson DC14 and DC17 animal below, compare them and choose the one that fits your needs better.
Dyson DC14 Animal versus DC17 Animal
images from manufacturer

Noise Level
DC17 is quieter than DC14.

Weight
DC14 is lighter.
DC14 weighs 18.6 lbs while DC17 weighs 20.79 lbs.

Cord Length
Both of these two vacuum cleaners have long cord.
However, the cord length of DC14 is a bit longer, it is 35.4 feet while DC17 has a cord length of 35 feet.

Bin Capacity
DC14 has a bigger bin, but just a little.
The bin capacity of DC14 is 0.71 gallons while it is 0.625 gallon on DC17.

Maneuverability
The DC17 is easier to push on carpets than the DC14.

Suction Power
DC14 has a suction power of 250 air watts while DC17 has 220 air watts.

Turbine Attachment
The turbine attachment of DC17 works better than the DC14.

There are many users said that the DC17 picked up stuff better than the DC14. But some also complained that DC17 pulled the fibers from their carpets. So be careful to use the DC17 on delicate carpets.