Moving the control panel to the upper right despite this making no sense on the massive iPad screen as compared to the iPhone X this feature was developed for.
Making the new floating dock ... and then making the gesture both to raise the dock and to open the app switcher the same gesture, with only fractional timing between them.
And that's not all. There's an additional context menu on Dock items now if you hold them, but ... you also need to be able to hold on a Dock item if you want to drag it up and make a floating window. Once again, fractional timing differences: hold too long and you get the menu instead. Hold too little, and instead either the app switcher comes up, or worse, it tries to drag the whole dock up, even though the dock is not a movable element. So about half the time when I try to drag up to create a window, instead I wind up moving the actual dock a fraction of an inch, and then it bounces back and nothing else happens.
There's also new "cleverness" about how windows are organized, and by cleverness, I mean "Why in the nine hells would I want this?" Previously, if you made a floating window, it was just that app, and you could swipe it in and it would always be the same app regardless of whatever full-screen app was currently open. For example, I commonly would make my IRC client the current floating window, so I could swipe over to it while watching Youtube or reading in Firefox to check chat.
Except now, the current set of windows is app-specific. If I'm in Firefox and I make a floating Discord window, and then go switch to Youtube ... that window is gone. Swiping in will instead bring either nothing, or whatever window I happened to create the last time I was in Youtube. This constantly results in confusing surprises and manually having to reopen windows.
Oh, and they redesigned the Reminders app, and in the process managed to screw up my notifications and delete or corrupt several important medication reminders, so thanks for fucking with my health, Apple.
The rest of the changes are mostly useless or cosmetic. The only vaguely useful thing is something they should've done years ago, which is expanding the app grid dimensions to something more sane for this resolution. The rest just feels like overblown marketing hype, a push for a new "desktop-like" iPad feel ... without any features that actually make it feel like a desktop.
Pointless.