I am not a fan of the new interface. This does not improve anything for users. It just changes the side a menu is on and forces users to change they way they interact with a document and how they work in Acrobat every workday.

That said, if this is to remain this way... Make the menus smaller or allow the user to adjust them. There is a lot of white/empty space between the tools listed and the actual document.

I typically use Adobe while it is on half of my screen (I have a 22" monitor) so I can review/update data concurrently. With the menus open, it takes up over half of the viewing area of the Document. It also limits the view/usability when trying to organize pages within the document.

Lastly, Please leave comments and other menus closed upon opening a document. My first actions are to close these so I can read/view the document. If I need to see comments, I can open that function separately. If you are worried that comments will not be seen, put a small indicator on the side menu that shows or changes color when comments are present.