Having just done my MCC I can't agree more with DFC.
Had my MCC been on a familiar type, with a pilot of similar aptitude where we could both have easily kept up single pilot let alone with two we wouldn't have learnt half as much.
I didn't learn how to fly a CRJ nor how to operate every system on it. The fact that it covered ground at 3 times the speed I was used to combined with the slippery-ness of a swept wing jet when trying to get it to go down and slow down "allowed" us to get behind the aircraft much more easily. This highlighted the need to communicate, bring your partner up to your level of situational awareness, cross cockpit gradients, the need to define roles but also be flexible with teamwork and delegation of tasks in normal and abnormal situations.
I learnt far more about myself as a team player in 8 days by being constantly taken out of my comfort zone.
Lack of knowledge of the type is actually a benefit for some training situations as the temptation when your sim partner can't find a switch to have both heads in and no-one monitoring is overwhelming but unlikely to happen in a familiar type!
Again, I was fortunate to be crewed with a fellow student who's first language wasn't English because my learning was enhanced by the experience.
I learnt more about myself in 8 days than I thought was possible and always having to work as a team to keep up with the aircraft and the scenario's was some of the most rewarding flying (albeit in a sim) I have done.
Could I get a CRJ off the ground now, possibly but unlikely. Does it matter, no. Can I work with a team mate in a demanding and previously un-experienced situation, yes.
And for me that's the point of the course.
Obs