In Telerik version 2016.2.607.45, the RadGrid Excel Like Filtering Context Menu Style is Broken. The width and alignment is not 100%. When I drop the older Telerik.Web.UI dll and corresponding Skins dll in my project, the issue is gone. I have attached two images, one from the latest release, and one from the older version. You can see how the latest versions style breaks and does not show the menu correctly.
With the use of the "UseStaticHeaders"-Parameter all ARIA-Tags are gone in the rendered RadGrid. We need the support of WAI-ARIA in our application for our customer. Dont using this Parameter is no option for us. You are not telling this missing function in your documentation.