I did my MCC in a full motion sim (EAL's 737-200). Just as potkettleblack says, my next sim session was an airline assessment - in another full motion sim. Using motion for the first time is a whole new experience which is exciting and can be a little disconcerting - I'm awfully glad I'd had over 20hrs practice before the assessment.
Do the MCC in an FNPT2 / car / downstairs loo, whatever, you'll still get the same piece of papar. I just know that experience in a full motion sim helped me perform better in my assessment and helped me get a job. And the assessor is pretty unlikely to ask where and how you did your MCC, mine was only interested in how many hours each of us had.