At only 410-ish episodes, I'm not the best person to ask. However, I can say that the fillers are torturous. I only watch the anime, so going AO after AO is extremely discouraging.
Story-wise, it's still going strong for me. The first 100 episodes were great, the second hundred had some of the best arcs *cough*DesperateRevival*coughcough*, and the third hundred had Vermouth.