UPDATE: 3/9/2021:
I remain unimpressed with the stability of Big Sur. Many users (myself included) are reporting kernel panics when waking from sleep and trouble using external displays with laptops.
In addition, the update process introduced in Big Sur was supposed to *reduce* install time, but has actually done exactly the opposite. Given the number of bugs and requisite updates being released, updates are taking upwards of 45 minutes each, longer if you don’t have a fast internet connection. Details here: https://eclecticlight.co/2021/02/28/last-week-on-my-mac-users-are-losing-out-against-big-surs-sealed-system/
Another problem with Big Sur is the cryptographically signed system volume. This was designed as a security mechanism, but in daily use it means that your Carbon Copy Cloner bootable backup must be erased each and every time the operating system is updated – a problem Apple introduced in Big Sur.
I still recommend Mojave (MacOS 10.14.x) or Catalina (MacOS 10.15.x) and am not recommending Big Sur at this time.
November 12, 2020
Apple released Big Sur – the newest operating system for the Mac today.
If you’re looking for the quick and dirty “should I install Big Sur?”, the answer is no, not yet.
Read on for more details and information:
Big Sur leverages the changes Apple made in Catalina, when it was released last October. Catalina was the first operating system for the Mac that only supports 64-bit application software. Older 32-bit apps do not and cannot be made to run in Catalina.
In addition, Catalina requires startup disks (including bootable backups) be formatted in the new APFS format, which Apple only supports on SSD media. This means there are ramifications for your backups (i.e. you’ll need new backup drives), if/when you update to Catalina or, as of today, Big Sur.
My observations regarding Catalina remain true – here are more details from back when Catalina was released:
https://lansharks.net/2020/01/17/things-to-consider-and-know-about-catalina/
I spent much of the day yesterday arguing with the Big Sur beta installer – not a good sign for stable, hassle-free software. Today’s public release (a gargantuan 12GB download) *seems* better, and Apple released a software update only hours after the initial release – not a confidence builder for well-tested code. I’ve only had a few hours to put it through the paces – so far things seem to be working and it feels snappy on my 2018 15” MacBook Pro.
There are some pretty significant cosmetic changes in Big Sur – for those who aren’t a fan of Apple changing/moving things around, this may be a release you want to wait to install, when you have time become familiar with the new bells and whistles. Here is an excellent comparison of some of the different look and feel changes from Catalina and Big Sur:
https://www.andrewdenty.com/blog/2020/07/01/a-visual-comparison-of-macos-catalina-and-big-sur.html
Bootable backups of Big Sur now require the system volume be cloned using a new software mechanism from Apple known as ASR. The system resides on a cryptographically sealed “Signed System Volume”. That seal can only be applied by Apple; ordinary copies of the System volume are non-bootable without Apple’s seal. To create a functional copy of the macOS 11 Big Sur System volume, Carbon Copy Cloner has to use the ASR tool to copy the system, or install macOS onto the backup. The upshot is that your backup drive will need to be erased the first time you run a clone under Big Sur and your previous backup data will be lost. If this is problematic for you, you can re-run the initial backup of your Big Sur Mac to a new external hard drive. More about Carbon Copy Cloner and ASR here:
https://bombich.com/kb/ccc5/frequently-asked-questions-about-ccc-and-macos-11
So, my advice for now is to wait to download and install Big Sur. Give it and other third party software time to mature. And of course, I wouldn’t be me if I didn’t remind you to update your bootable clone backup immediately before downloading any software updates, especially new operating systems. And don’t run your backup again for a few days, until you’re certain everything is working as expected.