I noticed the deterioration after the let's call "Toy Soldier arc" ( for the sake of preventing spoilers). The quantity
of filler in that arc was what made me realize how weak One piece had become.
I think that was Ep 600 or so. Then again there were some good things on the horizon,
White beards rival and such
, but ehh the filler inbetween is just too much of a time waster. Each arc the filler just gets longer and longer. All though the quality of the fights I won't complain about because it does follow the Dragon Ball forumla nicely and the fighting scenes have stayed true to its early 100 ep roots.
I'll probably pick it up again in a few years, it's not like plot complexity is something I have to worry about. That's another thing I hate about one piece, let's be honest. It is geared towards 6-10 year olds. I could probably skip 100 episodes of one piece and still know what is going on because they explain and hammer the plot in so much, **** even the opening is 3 minutes long, and then there is also the part where they explain stuff at the beginning which is 1-3 minutes. It's pathetic because there is no complexity. I know it's skip able but just to give an idea who they are catering two in the show.
I'm going to wait 300 episodes and just make use of the online lists that show which episodes to skip, but of course even then there is filler within the episode itself.... I'm on the fence.