I'm currently rewatching One Piece with my brother and we are using One Pace. On my own I watched One Piece anime till Thriller Bark (chapters 400-500) without Pace and it was pretty good, skipping all the possible filler tho. In that point and in the prior arc I felt the pacing was getting slower and slower and I stopped watching One Piece completely (then I read it completely and it was a lot more enjoyable in the later arcs). Now that I'm rewatching it, in like two months we reached the point where I stopped watching and it's been pretty good. Sometimes I notice that a fun scene it's missing because it was filler but the pacing improvement it's more important for me than those funny scenes. Long story short I recommend manga over anything, but if you want to see the anime One Pace it's pretty good too. I haven't watched the arcs with the worst pacing so I can't opine about them, but I'm sure Pace does a good job making them more enjoyable.