I think the pros and cons of the SDKs should be more clear.
OpenXDK is open-source, free, and legal. Games built with the OpenXDK can be legally distributed as long as the game code allows it. This means you can provide builds of your game on websites, google projects, sourceforge, etc.
The Microsoft XDK is not open, free, or legal. Games build with the Microsoft XDK cannot be legally distributed and, if you do distribute them, Microsoft could take legal action against you... however unlikely that is.