Well, the manga is certainly incredibly long. I started when it was at 940~ chapters and finished when they were at 950 ish lol. But it doesn't seem fillerish or anything, I mean, sure there's filler, but it is interesting enough to slog through.
The manga is so long haha. I want to start it but I can't help but feel it'll take me ages. I just watched the anime and was satisfied with what I got. I heard from a lot that the anime ends it nicely anyway, since the manga just drags afterwards apparently.