Just to be clear, the work of Mike on Redactor is incredible... especially knowing from where he had to start: if you buy the official Redactor, you will honestly not be able to use it in your project and wish not to have spend money on it. As you see, the XenForo version of Redactor can be use in production. Now I still prefer MCE for many reasons:
- The dom management is still better (several developers have been worked with it for years)
- The plugin system is very flexible and for an integrator that is not a professional coder (and doesn't want or even technically can't rewrite an whole editor ^^) it is important
- The developers have already included some defaults plugins with the editor which means they support them => so they just have to be integrated inside a script to let users choose their options. It is basic.
- I really love to play with icon fonts. It's fun and good looking.
- The licence type. Some addons here were integrating mce3 to give users an editor (which was not the XenForo default one). Now, I think that legally they can't do the same with Redactor.
- The developers are active now with the release of mce4 and replies to questions providing you give them enough elements
