I'm 2000 miles away and in no position to judge what's better or worse, but from what I've read, the Archer Ave location is the only one selling products by the Bobak's Sausage Company. The Naperville, Burr Ridge and other places, now named "Frank B's" have signs up and a disclaimer on their website saying that as well.
Sounds like a pretty nasty family feud...and all too common (Rosati's, Vito & Nick's, etc)
Bob in RSM, CA...yes, I know, it's a long way from Chicago