The difference with Bitter Feud is that it designates two players, so that in a multiplayer environment, it would only affect two players. The cool thing about this, obviously, is that in a multiplayer setting, you need not be affected by the effects of the doubled damage.
Still, I can see Bitter Feud being a part of some very aggressive Red burn lists in Commander. Thing is, burn lists aren't extremely popular in the format. Still, if ending games quickly by doubling damage is something you want to do, then Bitter Feud is definitely worth a look to play alongside these other two cards.