A lot of "service" characters blown up into major, defining roles (Sanji and Chopper)
It's not a quest that involves a successive set of bigger and bigger bosses necessarily. The bosses are also not all the same organization.
The handsome, polite butler isn't just a background character, and he's not a good if excessively proper and conservative man.
The women are equally competent as the men, and especially in early chapters, frequently smarter and more cunning.
No spiky hair.
On the power-level scheme, there's also no "formal transitions". Sanji doesn't ever have to take a test to qualify him as the next level of cook or kicking bloke, and Captain Morgan is the only one concerned with ranks.
Prettiness and goodness don't align. You have to admit bad guys like Mihawk, Kuro, Kuroobi, Smoker, and Alvida 2.0 are more fetching than Luffy and Zoro (dares not suggest Usopp isn't handsome around here ^.^)
The coward isn't comic relief.
Comic characters still can have touching stories (Gaimon)
There's no collecting. No "we must get the 40 keys to the gate of Raftel", no "we must amass all the Devil Fruits cos Sanji is making Nami one hell of a fruit salad"