Which is better?
Bavarian Grill is really a beer place not a food place. There food is not horrible, but generally taste like it's prefab out of a bag. For home cooking German http://www.everythinggerman.org/ or Kuby's are both better food wise.
Jorg's is good, but I would try it during the week. They get to busy on Saturday and the Schnitzel can be soggy.
Do you like Schzitzel or German specialties better? The crowd can be lively at both especially the later in the night and the more beer is served. I like Jorg's because the atmosphere is a bit more intimate and the food seems a touch better. If you are after a "German" party atmosphere then by all means go to Bavarian Grill. I think Bavarian Grill has a better beer selection if that is any determinate to you.
Jorg's is Austrian and Bavarian Grill is German.
Schnitzel at Jorg's is probably the way to go.
German Specialties (Schweinehaxe, etc etc) is the way to go at Bavarian Grill and they rotate depending on the season.
Both will have brats and neither of them are mindblowingly good brats. If brats is what you desire I would say go with Jorg's or hold off and go to Kuby's. Focus on the mains at Kubys as the sides are terrible.
If at any of the places and the accordian player is there feel free to chat up with him about polka if so inclined, he does know his stuff!