All’s good here...
iPhone 7+, iPad Pro 9.7”, Series 3 Watch and 2018 MacBook Pro all updated.
So far I’ve seen zero O/S bugs - although Hazel on my Mac is a dead duck until the devs release a new version of it (which I knew about going in to Catalina).
That said, aside from having to give the MacBook a double-tap mid-install, the rest went just peachy.
Battery life on all mobile devices seems just fine, not noticed any ill-effects. Not saying there aren’t bugs, just that I’ve personally not come across anything obvious - and I’m not alone either: Anecdotal evidence from co-workers (and aren’t most of these issues anecdotal?) also seems to be the case of “all quiet on the Western Front”.