I've pretty much elimiated the closer role from all my teams. They typically are your best releiver, but by confining them to the traditional closer role, they might not be used in the high leveraged situations in the 7th or 8th innings, which can often make or break the game.
Make your best relievers SuA, make your next tier of relievers SuB. Don't worry about who gets the save, that's just a stat.