There should be a way to mark a message read via a keyboard shortcut and/or menu item. This would then allow for the ability to highlight multiple articles and mark them all as read, rather than having to go through them one by one.
The only two options for marking articles as read are very limiting. I don't use "Next Unread", and the time for marking an issue as read is sometimes too long. Plus, there are times when Vienna highlights an article by itself (i.e. without user input), and then marks that article as unread without the user actually having read it.