Mine would have to be not being able to witness the Aokiji/Akainu fight. I've long accepted that Oda just isn't that good when it comes to writing fights compared to other authors but in almost every other instance between prominent people fighting in the verse Oda gave us something like a clash or a nicely drawn panel. You'd think a fight that has so much significance would atleast be shown to some extent. What's the thing that disappointed you the most?