Hmm, very mixed feelings about this opening.
I guess I'll cover the song first. Very upbeat and got me quite pumped up. Not the best one we've ever gotten but it certainly meets expectations. No complaints.
As far as the animation goes…what the heck? The outfits were actually fine, I feel, but were overused. Should have just kept them for the first 15-second segment and title card and then switched to normal clothes. Nami's outfit is just fine, I actually like it, but Robin's is uh, yeah, just look at that one screenshot someone posted. Does not leave much to the imagination. But that's the trend lately. May as well change Robin's profession on the ship from archaeologist to call-girl.
I actually REALLY liked the beetle chase. It was long, yes, but there were so many small details that made it look like the animators were actually trying, like Luffy's arm stretches and Robin propping the table back up.
Not crazy about the fan-fiction fighting against the admirals. Although I do think the monster trio probably could hold their own for...at least as long as the anime is showing, so I won't complain about that.
Blackbeard pirates being there, in their pre-timeskip designs, felt even more random and stupid. And having dialogue mid-opening really, really does not sit well with me. Greatest offense of the opening, in my opinion.
Dressrosa scenes all looked very nice and I wish they'd taken up more space in this opening (unless they're all recycled footage from the episodes themselves, that tends to irk me). The Mexican-standoff in particular looked AMAZING. The Donquixote Family shot was also great (and they're even properly arranged by the 3 units).
So yeah, not terrible. But not great either.