Well I believe the advantage is getting a guaranteed call from Ryanair for the final assessment plus learning a lot that will be useful later on if getting a job at Ryanair or at least at some other airline with 737-800 NG if not successful at the final Ryanair assessment. Plus at other airlines where there is a wide choice of aircraft that can be offered as for example at LOT Polish Airlines from the airline point of view it could be probably more useful to send the cadet on 737 TR than for example on Dash TR since the cadet is already prepared for 737. If someone does not aim at Ryanair they can still do the casual APS MCC at VA. I am very happy that I can now choose official Ryanair assessment not only at Sky4u and AFTA (no info about the course there).
What I wonder about is if its VA or Ryanair who decided/designed the extra assessment before APS MCC. Since there is no info about it on VA website. So I wonder if its something simple like the Ryanair online pre assessment or if its something extra that only candidates applying for VA APS MCC have to pass. Because it would not be fun if it was something like the German DLR where you have to use a lot of time to prepare things not relevant to flying (according to the thread describing the DLR).