RadNavigation can be setup to expand on hover (see demo - http://demos.telerik.com/aspnet-ajax/navigation/functionality/expand-on-hover/defaultcs.aspx). However, when the menu is collapsed to the More (hamburger) menu this functionality is lost. If the nodes don't have a navigate url they can be clicked to open the sub menu, but if they are set to navigate then clicking will navigate instead of opening the submenu.
A Vertical Orientation option would make the control usable as a side bar / sub navigation menu. Currently, we're using a PanelBar to achieve this functionality, but it lacks the Adaptive behavior of the Navigation control.
while replacing my RadMenu for the new RadNavigation, I was forced to stop because the RadNavigation does not support columns like the RadMenu can e.g. <telerik:RadMenu runat="server" ID="radMainMenu" MaxDataBindDepth="2" EnableRoundedCorners="true" EnableShadows="true" EnableTextHTMLEncoding="true"> <DefaultGroupSettings RepeatColumns="2" RepeatDirection="Vertical" /> </telerik:RadMenu> Keep up the good work, Thanks.