Apparently there is, given that Zoro could not use haki before the timeskip but could after.
Oh, which is why when Zoro was going up against Enel, Aokiji, and Kizaru pre-timeskip, he was able to affect them even slightly, given that he had the ability to cut steel, which is equivalent to using haki, and was using it consistently throughout the story from the time he beat Daz to the time they all got separated. Must have missed that.
Oh, which is why when Zoro was going up against Enel, Aokiji, and Kizaru pre-timeskip, he was able to affect them even slightly, given that he had the ability to cut steel, which is equivalent to using haki, and was using it consistently throughout the story from the time he beat Daz to the time they all got separated. Must have missed that.