He's not ready for Berto or Clottey, not saying he won't eventually surpass those guys, but I'd favor either to beat his soundly as it stands today (Well Clottey of when he was active).
Porter is never going to have it unless he completely adjusts his style into that of a boxer-counter puncher, he wants to be a pressure fighter but he lacks footwork, defense, and power to be effective at it.