RadTextBox need to include the ability for Columns. right now any docx that has a column gets stripped out when loaded. most business documents we deal with have columns. I have found this feature in other competitive products so i hope Telerik has on on the roadmap and implements it soon.
Actually, this is not a problem with the Import from Word functionality of RadEditor, but with the way MS Word content is rendered in the browser. You can see that when you save the Word file as HTML file the columns go away: http://screencast.com/t/im6lDGx6kPja