Self-explanatory. 15 years ago I would have said Chavez slightly. My opinion has changed. I'd consider Arguello greater.
I'd say Chavez is greater, but barely. Better is difficult to say. I think I'd pick Chavez to win at 135, though.
Arguello is my all time favorite boxer of all time but I think Chavez edges him achievement wise. In a H2H match I think Arguello has the advantage at 130 and 135.