What users need in the new interface...

Fellow users, please add or vote up the features that are most critical for you.
(Interface-related only, not new features or utilities.)

ONE:
A totally customizable set of toolbars — left, right, top, and bottom of the application window, and also on a side monitor.

— User determines which toolbars are visible.

— User can dock or float them anywhere, including on a second monitor that's outside the application window.

— User chooses which tools are in each toolbar.

— User chooses whether each tool/utility is represented as an icon only, icon + text label, or text label only.

— Let the user develop a custom toolbar with the individual tools they use most often, and let them dock or float it anywhere on their computer screen. The majority of professional users use 5-10 tools regularly and not an entire tool panel.

— Allow all panels / toolbars to be resized to fit the user's screen and needs.

— User can save this setup as a custom workspace that can be reset, changed, and re-selected whenever the user needs to do so. (See Adobe InDesign as a model for this very helpful feature. See https://helpx.adobe.com/indesign/using/customizing-workspace.html and https://helpx.adobe.com/indesign/using/workspace-basics.html#Workspaceoverview)

— And make it easy for users to create their own custom workspace. K I S S.

Note: Adobe, when YOU determine which tools are in each panel, you prevent users from having ALL the tools they need for their tasks, and also make it more difficult to get to the specific tools they need.

Example that fails in the new interface: having only the Comments panel or Page Thumbnails panel open at a time on the right side prevents people from efficiently editing PDFs. The problem isn't really that you moved left-side panels to the right and vice versa — it's that some pairs of tool panels can't be open simultaneously.

TWO:
Make the program fully accessible to all users...
— Whether they have a disability or not.
— Whether they use an assistive technology or not.
— Whether they're on a full-screen monitor or small mobile screen.
— Whether they have a touch screen or not.

— Allow the user to control the color and contrast of the interface: dark mode, light mode, medium, black/white icons, and hi-contrast (for those with low vision or reading disabilities). Many of the colors you've chosen are not fully visible to those with various forms of color blindness and low-vision.

Note: Thank you for darkening them in recent updates. That helped.

— Allow the user to set the size of icons, labels, dialogue boxes, menu titles, and adjustment points.

— Let users set the text size of comments in the Comments panel. People on high-resolution monitors (used by most professionals) and those with vision and reading disorders can't read the comments easily enough. Let comment text scale up and down as the user needs.

— Hamburger menus (3 horizontal bars in the upper left) are NOT fully accessible to those with vision and mobility disabilities. Give users a choice of whether to have them in the interface or use traditional drop-down menus with text labels. Hamburger menus are best on mobile small screens; but they are cumbersome and clumsy on full-size monitors which are used by professionals in their daily jobs.

— Redesign some of the tool icons, especially those that are confusing (see attached screen capture). Consider removing some of the icons: there are too many to sort through quickly, too many that are esoteric with undecipherable icons. Text labels can be faster to recognize and translate across all cultures.

— Make every menu and toolbar accessible via the keyboard.

— Bring back keyboard shortcuts for zoom in/out and paging. And let the user arrange where their icons are located on the screen.

THREE:
Fewer pop-ups.
Please!

— Once the user has viewed a pop-up, let them permanently close it.

— And stop re-popping the pop-ups after each upgrade.

FOUR:
Clean up, minimize, and redesign the user preferences section.

It's overwhelming. Confusing. Poorly designed.

FIVE:
The default interface should be the "classic" version, not the "new experience" — at least until you rework it sufficiently and the user makes the choice to move to the new version.

— When installing a program update, warn the user that there's a new interface and let them choose whether to use the new one or keep the classic.

— When installing an update, retain the user's custom workspaces, tool panels, and preferences.

— And keep the option to Disable New Acrobat.

Thank you for listening to us customers!

And tap into the experts on the Acrobat prerelease/beta team. Most of us have worked with Adobe for decades and have helped develop the program since its its inception. Many of us teach Acrobat across many industries and know what customers easily grasp or stumble over. Some of us are professional UX/UI designers. And we know what customers need this powerful tool to do for them.