Using Classic Outlook on Windows for personal email, calendar, and contact management
Ben, add the Unread search folder to favorites by Clicking on the Unread saved search folder. When it opens up, you will see a Star (Add to Favorites) to the right of the Folder Name title in the view region.
IMO, this is better than nothing, but still doesn't provide the subject functionality. This will show you all Unread mail. What's missing is a view to both Read and Unread email with priority giving to Unread without having to change filters or folders.
GMail does this a little better by providing collapsible Unread and Everything Else regions in the same view.