None of them, the characters themselves have been fine. Not giving Nami, Usopp, Chopper, or Brook their own fights/victories against notable opponents was a tremendous mistake in a long line of same, but for what little they were given, they made it work. Robin, Franky, and Jinbe all did their job as well as reasonably expected, and Zoro/Sanji also got their moments…hell, if not for the fact that the sentient dildo once again sucked up all of Daddy Eiichiro’s affection, I’d say this was the best post-skip arc for the entire crew, and maybe it still is, considering the competition.