Advantages of upgrading Sonoma to Tahoe on 2020 iMac?

For a 27-inch 2020 Intel iMac, macOS Tahoe 26 offers some useful improvements over Sonoma, but the advantages are more limited than on an Apple-silicon Mac.

Tahoe's principal additions include a redesigned interface, a significantly expanded Spotlight, the new Phone app, Live Activities, additional Control Center and menu-bar customization, and updates to Safari, Messages and other built-in apps. (Apple Support)

Apple officially supports the iMac (Retina 5K, 27-inch, 2020) with Tahoe. (Apple Support)

The major limitation is Apple Intelligence. 

Its Mac features require Apple silicon, so those capabilities are not available on your Intel iMac. (Apple Support)

There is also a security-support consideration. 

Apple does not guarantee a fixed three-major-version support period, but its current release history shows security updates for Tahoe 26, Sequoia 15 and Sonoma 14. (Apple Support) 

If Apple continues this pattern, moving to Tahoe would put the iMac on a newer major version within that group.

As of September 14, 2026, Apple has announced macOS 27 Golden Gate and lists it as available starting September 14. 

Apple does not list the 2020 27-inch Intel iMac among its supported Macs for macOS 27. (Apple)

Bottom line: If Sonoma is working well and you do not need Tahoe's new features, there is no compelling functional reason to upgrade. 

If you want the newer interface and Spotlight improvements, the Phone app and Live Activities, or you want to move to the newest major macOS version officially supported by your iMac, Tahoe is a reasonable upgrade.

Before upgrading, Apple recommends making a backup, such as with Time Machine. (Apple Support)

Apple: How to upgrade to macOS Tahoe

Apple: macOS Tahoe compatible Mac models

Apple: macOS Tahoe security releases

allfive wrote: Is there any useful upside to upgrade from Sonoma to Tahoe on a decently spec'd 2020 iMac?

Not in my opinion. I suggest going to Sequoia for now, in which case you will have at least one more year of "official" support for it as well as for apps that require it. You can always upgrade to Tahoe later if you feel the need.

Users have a "love it or hate it" relationship with Tahoe. If you haven't seen it in operation or read reviews, I suggest doing your research before committing to an upgrade. Here's a roundup of Tahoe's new features ... see if any of them feel indispensible; and remember that you do not get Apple Intelligence on an Intel Mac. Also check to see if any of your apps will also require an upgrade (for a fee!) - quite a few do.

Sequoia is quite stable on my Intel Macs.

I would suggest upgrading from Sonoma to Sequoia.

When Apple releases macOS 27 (Golden Gate), Sonoma will fall off the list of the "most recent three". It will stop getting the latest versions of Safari. Adobe, Microsoft, and others like them will likely drop support for Sonoma – especially for new installations of their applications – soon afterwards.

Sequoia will still be one of the "most recent three". You can always upgrade to Sequoia, and later decide that you want to upgrade from Sequoia to Tahoe. But if you upgrade to Tahoe first, it will be hard/risky to downgrade, and put Sequoia on your machine instead.

You can get Sequoia using the link in

How to download and install macOS - Apple Support

Yes! you get the newest features and you get nessecary security updates for your Mac

• The ensuing years of bug, performance, and security fixes not present with Sonoma.
• Some third-party vendors will drop application support for Sonoma after Golden Gate is released.
  • Apple's Pages, Numbers, and Keynote will never be updated on Sonoma.
• Tahoe 26.* is the last supported operating system on a 2020 iMac.

Owl-53 wrote:

As of September 14, 2026, Apple has announced macOS 27 Golden Gate and lists it as available starting September 14. 

Apple does not list the 2020 27-inch Intel iMac among its supported Macs for macOS 27. (Apple)

macOS 26 (Tahoe) is compatible with most Apple Silicon Macs released to date – but only four Intel-based models.

macOS 27 (Golden Gate) is compatible with all Apple Silicon Macs released to date – and no Intel-based models.

Servant of Cats wrote:

Owl-53 wrote:

As of September 14, 2026, Apple has announced macOS 27 Golden Gate and lists it as available starting September 14. 

Apple does not list the 2020 27-inch Intel iMac among its supported Macs for macOS 27. (Apple)

macOS 26 (Tahoe) is compatible with most Apple Silicon Macs released to date – but only four Intel-based models.

macOS 27 (Golden Gate) is compatible with all Apple Silicon Macs released to date – and no Intel-based models.

You are right the Intel 27" iMac does not qualify for macOS 27 Golden Gate

As we are also correct is saying and quote

“ Apple officially supports the iMac (Retina 5K, 27-inch, 2020) with Tahoe. (Apple Support) “

Apple does not list the 2020 27-inch Intel iMac among its supported Macs for macOS 27. (Apple) “ 

You will get updates, fixes and security fixes longer than older systems.