I just downloaded the Winforms demo and loaded up the first demo app -- the notepad example.
The app does not seem to support some basic functionality of the ribbon bar because the ribbon bar de-selects the text in the text editor.
Example:
1. Highlight some text in the editor.
2. Click the Font drop-down box to select a different font.
3. The text is de-selected so that when you select a font, nothing happens because no text is selected.
The buttons for Bold, Italic, etc, work when setting the text to the option, but not when trying to set it back.
I assume this is just a bug in the demo app...but it's probably something that should be fixed since it's the first thing prospective customers (like me) will see after downloading the demo.