You can safely revert to older version of firmware, so have no fear of experimenting with the new stuff. Just do make sure you revert the firmware if you revert Cura back to 21.08 – the changes to the firmware are incompatible (for no comprehensible reason) in ways that can lead to physical damage to the machine if you don’t have the right combination of Cura and firmware.
I tried the new firmware eagerly – upgraded both my TAZ 6 and my Mini. It was an unmitigated disaster; despite claims of being production-ready, the new Cura (as well as the firmware) were far, far from finished. It also had a serious performance problem – there was only a single computer in the house that had the horsepower and graphics card to run it (and no chance I was getting that computer from my wife to put in the basement by the printers!)
So, I downgraded to 21.08, put back the latest firmware known to be compatible with 21.08, and I’ve been happy as can be for the past 9 months or more. I did ask here what I was missing, and while I guess there are some new Cura features, none of them struck me as compelling enough to want to purchase a new laptop just to run it – not to mention making it worth the pain to deal with the horrible materials-editing and saving mechanism that the new version features.
I’d prefer not to be left too far behind, I keep hoping that someone will figure out what the graphics problem was that makes it not work on anything but the latest graphics hardware, and that someone will figure out the caching problems that have you manually delete all the settings and cached data, and that someone will figure out how to make it easier to customize, save, and import materials and quality settings. But I keep watching, and haven’t seen any commits to the source repository that would indicate they’re addressing those issues, so I expect the engineers are all busy squashing bugs (and adding support for the new hardware). Someday…