Some weapons have beneficial attributes (e.g. increased healing), which is a trade-off for worse stats. Other weapons have negative attributes (e.g. Stagger Lock) which is a trade-off for better stats. None are objectively better than others; it depends how you use the characters. For instance, I have Fang equipped with her weapon that has Stagger Lock, because it has the highest combined Strength and Magic stat. She is a badass with it, and I let my other two characters, who are predominately Ravagers, cause the stagger.