I recommend that you never ever use FCP as your defence if you are trying to win the game. Most teams simply do not have the players required to run an effective FCP. While you might notice a few increased turnovers in the beginning of the match this will not continue for the entire match. FCP will kill your defence, it will completely tire out your players, it will cause you to lose a lot of rebounds, and more often than not it will cause you to lose the match (unless you are a far superior team).
If you happen to have all of your starters having great OD, great ID, and great Rebounding as well as very high stamina then it might be worth trying.