I have never used it successfully. 
I documented my efforts to get it do some basic profiling, and overcame the first couple issues, but ultimately gave up (see my last post in that thread). I talked with @Lukeo who is the main champion of this machine we agreed that it needs some major overhauls.
I know that @emerson did successfully use it for facing a piece of wood, where XY accuracy and rigidity is not very critical. It could also probably do ok profiling very thin wood or plastic no thicker than 1/4".