Updated my wife’s Series 5 and my SE - it took about 30 minutes each for both. But I had to manually start the update - both iPhones said that the automatic update had failed because the watches were not on the charger - but of course they both were. I have had this failure many times for updates, but usually I just wait and eventually it works. This time my wife wanted the Snoopy watch face - and that needs both iOS17 and the Watch 10 update to work. Now we have Snoopy! (She has been using the Mini Mouse face - and Mini can read the time, but only when she wants - that function would disappear for months and the. reappear again. I asked a Store “Genius” and they said they knew about it, but had no solution. Maybe Snoopy willl be more reliable.)
David