I would have loved to see the Straw Hats, and Robin in particular, to meet the Gorosei under different circumstances, not immediatly with a fight.
I would have loved to see a scene where Robin is brought before the Gorosei and where she recognise the voice of the men who talked to Dr Clover right before the Buster Call of Ohara, and confront them over their order to destroy her homeland and millenias worth of history, as well as the orther atrocities commited by the World Government, and where they defend their actions and bring up some good points to justify their actions, while glossing over their and the Celestial Dragons monstrous actions before any physical confrontation.