If you are deciding between Shark Navigator Pet Pro Zero-M Upright Vacuum ZU60/ZU62 and Shark Rotator Powered Lift-Away TruePet Vacuum NV752 (or NV750,NV751,NV753,etc.), the comparison info below may help you purchase the right one.

images from Shark official infomercials

In fact, these two Shark vacuum series are quite different. The NV752 is from the Rotator series while the ZU60/ZU62 are from the Navigator series. The main difference between them are as it follows:

Zero-M Technology (Self-Cleaning Brushroll)
The ZU62 is a newer model, equipped with the Zero-M Technology. According to Shark, this new technology helps remove short and long, human and pet hair from the brushroll. How does it work? There is a bristle guard and comb that work together to separate hair from the brushroll and send it straight to the dust cup.
Whereas the NV752 launched before the Shark applied the Zero-M Technology, so it does have this self cleaning brushroll design.
If you want to try the Zero-M nozzle design, then buy the ZU62.

Check Shark ZU62 Price at Amazon

Dust Cup Capacity
The ZU62 has a much larger bin. Its dust cup holds up to 2.8 dry quarts versus 1.5 dry quarts on the NV752. With a bigger dust cup, the frequency of emptying will be lower. This is a good feature when cleaning large house.
If you prefer a big dust chamber, ZU62 fits your needs better.

Versatility:
NV752 is more versatile, it features the Powered Lift-Away which allows you to detach the pod from the vacuum and you still can use the motorized tools.
This is pretty useful when you want to vacuum underneath those low profile furniture. For a normal upright vacuum, such as the ZU60/ZU62, without this feature, such work cannot be done unless you move the furniture.
The lift away feature is also convenient for cleaning high and low areas around your house.

images from Shark official infomercials

Headlights
The NV752 has LED headlights on the handle and floor nozzle to help reveal hidden debris and clean dark spots. While the ZU62 does not have any headlights.

images from Shark official infomercials

Check Shark NV752 Price at Amazon

Control Button Location
The NV752 On/Off button and Surface Selector are placed on the handle for quick reach, while the ZU62 control switch is located at the top of the pod, you may have to bending over to turn on/off or change surface setting.

images from Shark official infomercials

Brush On/Off Control
When you switch the floor selector to Hard Floor setting, the brush roller of the NV752 will be shut down whereas the ZU62 brushroll keeps spinning.
So, if you want a suction only mode to vacuum hard floors, buy the NV752 Rotator Powered Lift-Away.

Surface Selector:
The NV752 has 3 settings: Thick Carpet/Area Rug, Carpet/Low Pile and Hard Floor.
While the ZU62 has. 2 settings: Carpet and Hard Floor.

Suction Control
The ZU62 has a suction control collar that allows you to release suction when needed.

images from Shark official infomercials

Whereas the NV752 does not have such suction adjuster. It only provides two suction levels. When choosing the Thick Carpet/Area Rug setting, it provides low suction, where setting to Carpet/Low Pile and Hard Floor, it provides high suction.
If you want one with suction adjustor that allows user to reduce suction power to vacuum like area rugs, curtains,etc., just pick the ZU62.

Check Shark ZU62 Price at Amazon

Hose Length
The ZU62 has a much longer hose.

Attachments
There is also difference between the attachments included, but accessories can be bought separately if you want.
As for the ZU62 and Rotator True Pet NV752:
ZU62 comes with a Duster Crevice Tool, an Upholstery Tool, and a Dusting Brush.
NV752 comes with a Crevice Tool, an Upholstery Tool, and a
TruePet Mini Motorized Brush(or Pet Power Brush which is air driven). (Old version used to include a hard floor attachment and a caddy for canister function, but they are no longer included anymore.)
Please note that attachments may vary from time to time, and different retailers may offer different accessories with the same model, always check it before buying. Buy from retailers that you can easily return the item is a good option if you are not sure what are included.

Weight:
The NV752 is a bit heavier.
The NV752 weighs 16.7 pounds whereas the ZU62 weights 16 pounds.

Dimensions:
Rotator Powered Lift-Away: 13.2 L X 11.9 W X 45 H
Navigator Pet Pro with Zero-M: 9.8 L X 11.9 W X 45.2 H

Similarities:

• Cord Length:
  The Rotator Powered Lift-Away series used to have a 30-foot power cord. But, according to recent user reviews, the Rotator Powered Lift-Away is now equipped with a shorter cable which is 25-foot in length.
  The ZU62 have a 25-foot cord.
• Power Specifications:
  120V,60Hz,1150W,9.5A
• Cleaning Brushroll
  The brushroll cover is at the bottom of the nozzle, the brushroll is not removable. When cleaning the brushroll, you flip over the nozzle to get access to the roller to clear away anything wrapped around, such as string, hair, and carpet fiber.
• Anti Allergen Complete Seal Technology plus HEPA filter to lock in 99.9 percent of allergens and dust inside the vacuum, and expel cleaner air. For people who suffer from allergy and asthma, this feature is a plus.
• Both feature swivel steering.

Check Shark NV752 Price at Amazon

Read Manuals to Learn More:
Rotator Powered Lift-Away Manual:
https://m.sharkclean.com/include/pdf/manual-nv650.pdf
Shark Navigator Pet Pro Upright Vacuum with Self-Cleaning Brushroll Manual:
https://www.sharkclean.com/include/pdf/manual-zu60.pdf

Are you debating on buying:
Shark APEX DuoClean with Zero-M Powered Lift-Away Upright AZ1002
or
Shark APEX DuoClean Speed Powered Lift-Away Bagless Upright AX912?
If yes, I will show you some differences between them below to help you make an informed decision.

images from Shark official site

Zero-M Technology
If what you are looking for is one with Zero-M self cleaning brushroll, then buy the AZ1002. The biggest difference between them is the Shark AZ1002 features Zero-M self cleaning brushroll whereas the AX912 does not.

Bin Size
Another noticeable difference is the dust cup size.
The AZ1002 is a full size upright, has a larger bin which holds up to 1.5 dry quarts, whereas the AX912 is a compact size upright, has a smaller bin with capacity of 0.9 dry quarts.
A larger dust cup means you do not need to empty as frequently as using a smaller bin.

LED Headlights
The AZ1002 equipped with LED headlights on nozzle and handle whereas the AX912 has headlights only on nozzle.
Headlights on handle is useful for cleaning low light spots with accessories attached.

Check Shark AZ1002 Price at Amazon

On/Off location
The AZ1002 has the control on the handle whereas the AX912 has the button at the top of the pod.
Control on the handle allows you to turn on/off the vacuum without bending over. This is more convenient than control button located at the vacuum pod.

Power Specifications
AZ1002: 120V, 60Hz, 1350W, 11.3A
AX912: 120V, 60Hz, 900W, 7.5A

Accessories
The AZ1002 comes with a 12″ Crevice Tool, an Upholstery Tool, and a Pet Power Brush.

images from Shark official site

While the AX912 comes with a Pet Multi-Tool, a MultiFLEX Under Appliance Wand, a Duster Crevice Tool, and an Anti-Allergen Dust Brush.

images from Shark official site

12″ Crevice Tool: for cleaning in tight spaces, between couch cushions, and in hard-to-reach areas.
Upholstery Tool: for cleaning large particle, removing pet hair and lint from upholstered surfaces.
Pet Power Brush: for picking up pet hair, dander, loose debris from upholstery and other surfaces.

Check Shark AX912 Price at Amazon

Pet Multi-Tool: 2 tools in 1, can be used as an upholstery tool, without the detachable bristle brush, for removing stubborn pet messes; or attach the bristle brush for cleaning stuck-on debris.
MultiFLEX Under Appliance Wand: This pivoting wand features a flexible elbow to cleans under, behind, and on top of appliances and furniture.
Duster Crevice Tool: Another 2 in 1 tool, the crevice tool gets into tight spaces, while the soft dusting brush cleans a multitude of surfaces.
Anti-Allergen Dust Brush: Designed for removing fine dusting and allergen particles from delicate surfaces and in narrow spaces.

Besides these tools, there are some other tools available to be purchased on Shark official site, such as a motorized pet tool for the AZ1002 to clean upholstered surface.

Warranty
The AX912 carries 7 year limited warranty while the AZ1002 is backed by a 5 year limited warranty.

Weight
Since the AZ1002 is a full size, it is a bit heavier than the compact size AX912, like about 2 pounds.

Color
The AZ1002 is Espresso whereas AX912 is Orange.

Similarities:
Anti-Allergen Complete Seal System with HEPA filter
Capture and trap tiny particles down to 0.3 microns, emits cleaner air. This feature is a plus, especially for people who suffer from allergy and asthma.

Powered Lift-Away
The lift away pod can be detached from the vacuum cleaner to extend the reach of the motorized nozzle, which means you can use the low floor head with the wand attached to get under low profile furniture, thus you do not have to stop to move those furniture while vacuuming. This will save you much time and effort.
And you can also remove the wand, and insert the handle directly into the motorized cleaner head to clean carpeted stairs or other carpeted surface.

Check Shark AZ1002 Price at Amazon

DuoClean Technology
Unlike traditional vacuum brushroll design, these vacuums equipped with two working rollers, one bristle brushroll and an additional soft roller, in the cleaner head, both of the rollers spin when cleaning hard floors and carpet. Shark claims that the soft roller help clean stuck on dust, small and large particles. It seems that the soft roller does do a good job on hard floor cleaning based on many users reviews.

Cord Length
Both have a 30-foot power cord.

Other things you may want to know before buying:
No Suction Control
There is no suction adjuster that allows you to reduce suction when cleaning curtains, area rugs, or delicate things.

No Pile Height Adjustment & No Brushroll On/Off Setting
There is no control to elevate or lower the rollers to fit different piles of carpet.
The only thing you can control is the surface setting. They have 3 settings to choose from:
Thick Carpet/Area Rug, Carpet & Low Pile, Hard Floor.
When cleaning hard floors, the rollers continue to rotate, the only difference between the 3 floor settings is the speed of the rollers. If you want to buy a Shark vacuum that allows you to turn off the brushroll, you can take a look at the Shark Rotator Powered Lift-Away NV750 series.

P. S.
If you are deciding between ax912 and az1000, az1000w, this article is also helpful. Because the difference between AZ1000,AZ1000W,and AZ1002 are just the attachments and color.

You can also download Shark AZ1002 and AX912 user guides to learn more:
https://m.sharkclean.com/include/pdf/manual-az1000.pdf
https://m.sharkclean.com/include/pdf/manual-ax910.pdf