IMO Kabuto summoning all those Edo tensei seemed like Kishi's way of saying that Kabuto has surpassed Orochimaru. As we furthered through the series, we've learned that he's acquired several of his old master's abilities (and even improved some of them), while still retaining his valuable medical knowledge. This, added with new abilities like learning Sage Mode, gaining most of Hebi/Taka's abilities, gaining the Sound 5's powers, and even absorbing part of Orochimaru himself leads me to believe that Kabuto has indeed surpassed Orochimaru. Even if he's not as "enjoyable" as the earlier dark Sannin.