Tonker and Leezy, what you are forgetting is that the next step after the MCC course is an interview and a SIM ride (hopefully).
While on a sim ride they want to see your MCC/CRM abilities, you can't tell me that they are also not looking at your general handling of the aircraft, and you also can't tell me that turning up to a 737800 SIM check- that it hasn't helped that you did your MCC on a 737400 instead of a kingair (or your car)....
Yes the MCC is purely to teach you to fly with two crew, but there is so much competition for jobs, especially right now, that you need to be able to stand out on a sim check, and having flown something simular before will give you the best possible chance on the sim check.. fact