This opens up a discussion that is too diverse for a simple answer.  Diffusion is a useful acoustical tool in a small room because a small room is, by definition, not diffusive.  It's principle utility is in capturing reflections that would not be directed to the listener and "capturing" this sound energy by scattering it making it audible sooner.  This has the effect of filling in blanks spots in the surround stage.  There are many types of hybrid treatments which combine diffusion, absorption, and even reflection to modify reflections.  I have developed such treatments that do actually combine diffusion and absorption but I use them for a vey specific purpose in the room.  My Q-FractorPlus is a treatment that is best used at the near speaker reflection points.  While it does have some absorption and diffusion, it also allows certain reflections to be passed on to the listener.  There are other examples for other uses.  If you have more information on the treatment you mention, it would be good to know its purpose before I can understand if it makes any sense for a room.  Too often, treatments are created without any real study or testing.  They just look interesting and seem technical.  Beware of products that do not have testing data.