Franky vs Sasaki had a lot of potential, but it's probably my least favorite Franky fight. It's the fight that felt most like an afterthought compared to the others on Onigashima. Nothing interesting was done with Franky's or Sasaki's characters, nor did we learn anything new. It wasn't bad, per se. It's just I shouldn't feel like Straw Hat fights are only quotas arcs are meant to meet.
At least with Franky vs Senior Pink, we got to learn stuff about Pink, and spotlight Franky's best character traits.