It's up to Beta 6, so that's a good indicator (at least for me) that it's stable enough to start using on the daily. I haven't run into any issues, but I cloned my drive to an external before I installed it…just to be safe. (I learned my lesson many years ago.)
I know there are dozens of changes and improvements, but frankly…I don't notice a huge change from Big Sur. Maybe it's because I keep my system pretty slimmed down and don't tweak a lot of the stuff that tends to break in these betas. Or maybe I'm just not that observant.
And the Safari tabs scandal? Whatever, dude. As long as they work (and they do) I won't get my panties in a bunch over how they're displayed.
Everything else I use daily is working just fine. Things seem a little snappier, but that could just be my impression because it's got a fresh coat of paint.
Fresh paint always works wonders.