The GM Fillibuster definitely works better than plain old "GM Fiat" (Nope, he's dead, bugger off, no you can't heal him, nope, nope, nope). And it works better than using the game mechanics to forcefully frustrate any / all efforts by the players. The only drawback it poses is if the group really doesn't like suspending the rules system to allow for better drama, and if they feel this way, you might want to have a talk with your group about everyone's expectations at the table.