Best: All the interesting villain powers. Like Aizen illusion powers.
Worst: Every defeated foe comes back as ally eventually.
So author gotta put random squad members, vice cap and 13 captains into fights. And Chad, and Renji, and Spada, and Rukia, and Vaizards, and Ressurrection, and Yoruichi, and the SS Royal Guard, and ... and they can't really do much because Ichigo has to be the mvp. And they had like 1 to 3 chapters in their fights, so it dragged arcs by a lot.
Plus: Ichigo is fighting someone who has some extra interesting trick, and the fight becomes a slugfest.
that was my main problem most of the times the characters win through powering through though its mostly Ichigo
I really liked when Gin used his Bankai and Shikai by hiding his zanpaktou behind his cloak at times to trip up his opponents I wish more ingenuity was placed on not just the powers but how the characters use the powers