You all should go to the Jolly Jug in El Monte. The beef dip sandwich is the best. The Philly Cheese Steak Dip as well.
I have had the Beef Dip twice and after inspection of the sandwich I noticed it's really cooked brisket style but sliced ultra thin. That is their secret and that is what makes it good. Most places with brisket like Arts in Studio City slice it thicker so it has a different feel therefore taste different besides any of the recipe differences. The way they cut the brisket at Jolly Jug gives it a texture and taste that is to die for. It's my opinion but it's the best brisket/beef dip I've had so far.