Madpuppet is committed to moving all development to Unity.
So I can release to all platforms including web versions at the touch of a button.
That is really the main reason.
As a development platform it IS pretty nice, though you do have to give up a little performance here and there compared to writing native code.
You can follow the progress of my first project (well, second if you count Dungeon Master's Toolkit, which is still very much alive but in hiatus).