Great to see so many previous attendees adding comments. Thanks all.
Ramy - MCA is a certification given to those who have passed the MCA Review Board as well as the MCM exams - The MCM certification is a pre-requsitite for taking the MCA (Exchange) Board. So only MCM's can apply to take the Board. The Board is a test of non technical skills on the whole, things like communication, leadership, tactics, strategy etc, those skills needed in addition to the technical for those who take on the Lead Architect role.
In short, MCA | Exchange is someone who can do the depth as well as the political and business breadth, MCM is about teaching and validating only the depth piece.