Adobe Acrobat Reader asks me why I would switch to the old interface, rejecting the new one. Simple. Old interface: Annoying sidebar always appears initially expanded, but does not obscure the document in any way; rather, the document is scaled down to fit screen appropriately. New Interface: Sidebar now on the left, obscures document annoyingly. Never do I need your sidebar items; I just want to read a document, not write a tome in PDF.