You are absolutely correct in noting that resizing the editor causes the page layout of the editor online examples to break, yet I would disagree with you about the feature being buggy. It is not. Resizing the editor works properly - and you can test this in a simple page with an editor, or in a page with a "less advanced" layout.
In case you encounter any problems with the resizing behavior in a simple page, or in fact, in your own layouts, please let us know in more detail and we would examine those immediately. On the other hand, in case you do not need this behavior, you can disable it with the simple CSS workaround provided in this forum thread (and later you will be able to do so by using the property).
the Telerik team