Thriller Bark was a chore for me, but that's only because I hated Moria, probably even more than Spandam. Usually the arcs that have terrible villains or main antagonists with shitty personalities, I usually just fall asleep or don't care much for the arc as a whole, unless there's something else that happens on the arc that overshadows what I detest.
This current arc isn't really that bad, but there are a lot of issues, and I am not a fan of Big Mom either, so I guess that makes it worse, but we have Katakuri so I guess it makes it worth while.
I'm not sure where all the hate for Dressrosa comes from, though I guess it can be from the Tontatta tribe and how much attention they were getting when no one really cared for them, but Doflamingo was an amazing character imo, and having Fujitora come on the island as well as Sabo made it even better, despite it being so long.
Punk Hazard was garbage and so was Fishman Island, but Thriller Bark was the absolute worst of the 3 for me.