For its size
The screen is 49 mm instead of the 45 mm on the biggest Apple Watch available on previous models. It also has a bigger Digital Crown and a raised side button to make it easy to use even with gloves on.
The bigger screen size makes it a bit easier to see your metrics in a middle of a workout.
For an Apple Watch, the Ultra is big but not as big as some offerings from Garmin and Suunto. It's huge for an Apple Watch but it's not ridiculously huge.
And for its size, the Ultra (61.3g) really doesn't feel as heavy as one might expect thanks to the titanium used in the construction.
For a different look
Most of the time, there's very little reason to upgrade an Apple Watch because they pretty much look the same every time a new one comes out. If you want something different in an Apple Watch, this is the one for you.
The Ultra is still square like all other Apple Watches but the bigger digital crown, the raised side button, the crown and side button guard, the raised screen, and the orange action button makes it different enough at least to look like you actually bought a new Apple Watch.
However, if you're on a budget and you want a different look, you can always get a third-party case like the Amband M1 (pictured below)
For the Action button
The action button is unique to the Ultra and not present in the Series 8 and the SE edition. It can be used for many things depending on your setup including starting a workout, turning on the flashlight, marking a Compass Waypoint, and more. If setup according to your needs, the action button could be extremely useful.
By pressing and holding the action button you activate the 86-decibel siren to attract attention up to 600 feet (180 meters) away.
For the rugged construction
The Apple Watch Ultra is made of titanium, which is known for being lightweight, tough, and corrosion resistant.
The Ultra has also been tested to meet MIL-STD 810H standards – a military test standard developed by the US Department of Defence used to determine if a product can withstand the effects of difficult environmental conditions.
For the brighter screen
The big 2,000 nits screen makes it easy to see even when out in the bright sun. The other Apple Watches only come with 1,000 nits of brightness.
For a more reliable and accurate GPS
The dual-frequency GPS antenna on the Ultra provides accurate location tracking even when surrounded by tall buildings or trees. The single-frequency GPS in lesser Apple Watches often struggle in such environments.
Data from the two GPS frequencies in the Ultra are combined to provide a more accurate distance, pace, and route calculations.
For the better battery life.
The Ultra has a battery life of up to 36 hours of normal use while the Series 8 and SE can only last up to 18 hours. That's twice the battery life.
On low power settings, the Ultra can last up to 60 hours.
For recreational diving
The Apple Watch Ultra is certified to 100 meters depth under ISO standard 22810:2010 and is EN13319-compliant. It can be used as a dive computer. Having a dive computer that's also an Apple Watch is very convenient can be very convenient for Apple users since you don't need to a have separate dive computer.
There's a new Depth app that gives you basic information for recreational diving like current depth, maximum depth, time underwater, and temperature. However you don't get depth monitoring past 40 meters.
With the Oceanic+ app by Huish Outdoors, the Ultra acts more like a pro dive computer. It includes times for safety stops, warnings of excessive ascent rates and decompression limits. You can also use it for dive planning and logging.
Unfortunately the Oceanic+ is a subscription-based app ($80/year), which may put off some people.
The Ultra is the most expensive Apple Watch at $799. Still not as expensive as Garmin's Enduro 2 ($1,099.99) but it's twice the price of the Series 8 ($399).
It's one way to show people you're not a poor. But if you really have the money to flex with an Apple Watch, check out Brikk's Lux Watch Omni custom Apple watch, which can cost up to $144,995. No, that is not a typo. It's close to one hundred forty five thousand dollars.
You want Apple's best-ever running watch
You want the Ultra because it's the most durable, has the best battery life on an Apple Watch, the brightest display, more accurate GPS-tracking, and all the other features mentioned above.