I will say the experience has been a pretty positive one overall, bugs and all. I don’t remember what the iOS 15 fiasco was about, but I always update on day 1 and has worked out well.
Examples of things that continue to work:
1) I have 2013 Apple TV’s in my classrooms, which still support airplay mirroring very well, so I am happy that Apple hasn’t broken anything yet.
2) You don’t realise how much you miss your Apple Watch until you go down marketing without it one day and then realise the hassle of unlocking your phone or making purchases with Apple Pay, or even just taking public transport.
3) There’s some fun synergy when using my MacBook Air and ipad together (like I take a screenshot on my laptop and annotate on it from my ipad with Apple Pencil), and I am looking forward to trying out universal control with iOS 15.
4) I have recently migrated over to iCloud Drive to save some money on my Dropbox subscription, and because OneDrive seems to have messed things up with their latest update.
Lots of little refinements that quickly pay for themselves in the form of improved productivity overall.