As Goth Guy stated, it's completely based on opinion.
My opinion is that it's the greatest of the arcs so far. The art has improved even over the GSC arc, the plot is deeper and more convoluted than those that came before, there is more interaction between what one might consider 'minor' characters, seemingly inconsequential things return later to immense effect, and most importantly the characters are deep and believable. Again, it's just my opinion, but my opinion is that it is by far the best of them.