MacOs 27 is a disaster. All of the sudden, I have 35% of a computer left to do any kind of work.
Among other signs of awfulness, macOS 27 (and 26 before it) half the battery life of my M1 Air, forcing me to stay on Sequoia for a 2nd year.
Apple software updates are always a downgrade. It's an opportunity to abuse customers that Apple just can't resist. If you're lucky all they do is break your muscle memory by moving buttons pointlessly.
26 felt like more of a disaster than 27! I waited about 8 months to upgrade to 26, and upgraded to 27 right away.
It's the iOSsification of macOS. Apparently, newer macBooks will now have touchscreen too ... once iPad OS and macOS are fully merged into OneMacOStoRuleThemAll, they'll finally lock down the bootloader on all Macs (why do you want to install anything else other an Apple OS?) and force all software install only through the App Store.