Casamayor. He had a **** load of world class experience at 135, and he knew all the tricks to the trade. Broner will be able to hang, but I think Casamayor takes him to school. Casa UD12
I have respect for Broner's heart and abilities despite his being a hopeless head case. That said, Casamayor was elite level or just a hair below and Broner is not. Casamayor by wide UD.
Joel was a very slick, crafty fighter in his prime. Although Broner didn't campaign at LW for very long, he did look like he could be a force at the division with his combination of speed, athleticism and power. His biggest issue IMO is his workrate (or lack thereof,) and I could see Joel outwork him to a comfortable decision. It would be a really good, tactical fight.