I can tell you from my experience that its down to the individual and not the aircraft you do your MCC. I did mine in simtech , altough not a great realism sim, I got the job. My sim partner during the type rating did his MCC coincidentally speaking on the B200 King Air, and as a matter of fact, the transition to a jet aircraft was a breeze for him.
And I think you guys might be confusing the FFS with FNPT2, as so far I haven't heard or came across Full Flight Sim which stands for full motion, which MCC courses don't use, unless you pay a fortune for the privilege.