There is good and bad news in iOS 13 beta 4; The good news is that the next version of iOS has been polished, with many bug fixes and at least one great new feature. The bad news is that new bugs have been introduced and that the sharing sheet is still much harder to use than the current version of iOS 12. But let's look at the new.
You can assign 'long press' to a mouse button
This is huge for users of mice with iPadOS. You can now assign several gestures and functions to your mouse buttons (start, show dock and many more), but now you can add by pressing long to that list. In iOS 13, a long press makes a context menu appear, which means it works the same as a right click on Mac.
You can now right click on the iPad, just as Steve intended. Well almost. When I try this, the mouse pointer jumps to the center of the screen, so it still does not work.
Smaller quick action menus
Talking about clicks with the right button: the quick action menu, the small bevel that appears when you press the start screen icon, is now smaller. You also have a new entry in your list: Reorganize applications. This places the application icons in the familiar jiggle mode, to rearrange. And, if you drag the icon while this menu is displayed, you will also enter the jiggle mode.
3-D Touch Duration Setting
On the iPhone, there is now a new configuration for the 3-D touch: Duration. This allows you to choose the time you must press before activating a view, pop-up window or other 3D touch function. At this time it does not exist on the iPad, so you can not use it to shorten the new right mouse button.
New voice message icon
Inside iMessage, you will now see a new icon to record a voice message. Instead of a microphone, it is a waveform icon, which matches the one found when you quickly see an audio file in the iOS 13 Files application.
The New Photos application icon indicates hidden duplicates
iOS 13 has new views Days / Months / Years, and in these hidden screenshots, and multiple versions of the same theme. Now, if there are more photos available, they will be indicated with a plus symbol and a number.
Small visual changes
There are some small visual changes. The action sheet is now whiter and less transparent. More importantly, it is terrible. In iOS 13, the sharing sheet has been completely redone. It has a new row of smart options for quick sharing at the top, so you can, for example, send a photo to a contact with a single tap. But it has also grouped all the shortcuts with the other available actions, without the possibility of choosing which ones are displayed. This is so bad that it should only be a beta problem that has not yet been solved.
Also, if you move the widgets bar from the home screen to the bottom, the Edit button has changed way slightly now It's a pickup instead of a circle.
And that's all we've found so far. As for stability, it is not better than the latest version. Some things are fixed, others are broken. This is a really painful beta process so far.