I'm inclined to agree with Laptrap's viewpoint over here, tbh. As is the case of any long-running shounen (Bleach, OP - you name it), a LOT of corners are cut. Shortcuts as far as animation goes are all too common and certain scenes don't get the attention they deserve. Which spoils stuff quite a bit. The only two long-running shounen that I've seen get good treatment are Hunter X Hunter 2011 and Gintama. But those are exceptions rather than the rule as can be seen in the Big Three and in stuff like FT and the like...
The anime cutting corners is kinda the reason I've completely dropped the One Piece anime at this point (apart from the horrendous pacing, obviously). And the same reason why I've been reading the Nardo manga but haven't been watching the anime. That, and fillers. Ugh. I mean, I stopped watching the anime after the pain arc but I did possess plans of getting back into the anime someday. But with me having spoiled myself to a degree with anime possessing decent animation as well as the fact that Nardo's manga's last arcs aren't really my fave, I'd have to say I've changed my plans since then.