I think just the TS itself screwed up a lot regardless of the quality of the arcs themselves. There was a hell of a lot of momentum and flow to OP before that.
Like, pretty much from entering the Grand Line to the TS there was this sense of continuity and overlap. Reverse Mountain flows with events, side characters and subplots into Whiskey Peak, Little Garden, Drum Island (with new events and sublots introduced throughout, like Ace looking for BB), Alabasta, Jaya, Skypiea, LRLL, W7, Enies Lobby, Thriller Bark, etc.
The TS just stopped it all and took away the momentum and sense of overlap and intertwined narrative. But then it did start its own running-on events with TB flowing into DR into Zou into WCI. Interestingly, it's as its built up several layers of momentum with the continuing stuff (like the Jap guys spanning across several arcs, and Carrot) it's started to actually get good again.