User blog comment:AYET/The worth of the Shichibukai to the Marines/@comment-5962458-20130529072238/@comment-6920514-20130530033225

I wouldn't say they are that weak and even if they were the new upgraded ones that briefly appeared in Film Z looked pretty powerful. I know Film Z wasn't canon but Oda still oversaw it so I would say it's a safe bet that they got a significant upgrade since the Strawhats' return to Saboady. After all, their base model was sitting by the Sunny for 2 years.