Is upgrade to Tahoe causing many problems

The main thing to keep in mind is that the reports you are reading need to be separated by which Tahoe release they describe. 

Problems reported with the original Tahoe 26.0 release should not automatically be assumed to apply to the current Tahoe 26.7 release.

Your 27-inch 2020 iMac is officially supported by macOS Tahoe 26. 

Apple lists the 2020 iMac among the Macs compatible with Tahoe.

It is not supported by macOS 27 Golden Gate, making Tahoe the final major macOS release available for this iMac. (Apple Support)

Since the initial Tahoe release, Apple has issued multiple updates containing bug fixes, security fixes, performance and compatibility improvements. 

The current Tahoe release is 26.7, while Sequoia is currently 15.8. Apple is still providing security updates for Sequoia. (Apple Support)

Therefore, comments describing significant problems with early Tahoe releases should not automatically be interpreted as describing the current 26.7 release. At the same time, it would be inaccurate to say that every Tahoe problem has disappeared.

There is another important consideration for your particular iMac: not all Tahoe features are available on Intel Macs. 

Most importantly, Apple Intelligence requires a Mac with Apple silicon, starting with M1. 

Your Intel-based 2020 iMac therefore does not support Apple Intelligence.

Some other Tahoe features are also dependent on the Mac model, operating system, language or region. (Apple Support)

Ultimately, only you can decide whether upgrading to Tahoe will meet your expectations. 

The relevant question is not simply whether Tahoe's early problems have been resolved, but whether the current Tahoe experience, together with the features your particular Intel iMac can actually use, provides enough benefit for you to make the change from a Sequoia installation that is already working well for you.

In other words, “Tahoe had significant problems,” “many of those problems have since been addressed,” and “Tahoe does not provide every feature on an Intel iMac” can all be true at the same time. The important factors are the current Tahoe release, your specific 2020 Intel iMac, and which Tahoe features you actually expect to use.

I have a 2019 MacBook Pro 16", the oldest Mac able to take the Tahoe upgrade to 26. For me, everything is working very well. I SENSED that the computer was running better with Tahoe versus Sequoia, but that was not something I quantitatively measured, it was simply my impression. I noticed some bugs being fixed in Tahoe that had been present (for me) in Sequoia. Note that Tahoe is now on 26.6.2 so it has had plenty of updates to address any issues that might have surfaced.

I think you would also be fine staying with Sequoia. Tahoe does make some security improvements.

we04ndy wrote:

Still using Sequoia on Imac 27" 2020 after reading of Tahoe upgrade issues. Have the issues been mainly resolved?

Sorry but you can read the exact same “upgrade issues” after every single version of macOS ever released. It’s like seeing sick people in a hospital and assuming everyone in the town is sick. Not true.

macOS 26.7 Tahoe is probably the last update other than security patches and is fully matured. It’s as good as it’s going to get. macOS 27 Golden Gate has just been released.

I’m running macOS 26.7 on my M1 Studio Max with only minor annoyances. There will always bugs

we04ndy wrote:

Still using Sequoia on Imac 27" 2020 after reading of Tahoe upgrade issues. Have the issues been mainly resolved?

Yes all the issue have been mainly resolved.

Apple has moved onto macOS 27 Golden Gate.

macOS 27 Golden Gate is compatible with these computers

macOS 27 Golden Gate is compatible with these computers - Apple Support