This is funny thing. People think it's okay when he is slightly OP, but guess what, people who mastered Shaco are terrifying and they also have whopping win rate on him. And they will still be terrifying, even after nerfs and even if there was another nerfs. They will always be, guess why? Shaco is a champion that can, in goo hands, deny anything from enemy team. Just his presence in match forces people to think differently, and mentality is a big part of the game, even if you think it isn't. After assassins rework his win rate was really high, second highest. In. Every. Single. League. And that's something you must consider. He really, really needed a nerf. Even with nerfs he is still great. I don't know much about Shaco, I didn't even play him after the nerfs but I have seen him and he still does very good with AP builds. So I can't tell if he got a bad nerf or good nerf. But in my opinions, this nerf was fine.
Also, what do you mean by "dont be fooled by statistics." ? Statistics are everything. They are the reason why champions gets nerfs/buffs. They show you if a champion is good now, how he performs. His win rate is still good, his damage is brutal as always and no, you don't get countered by just one item. And even if it was true, you can still buy mpen.
No, AP Shaco doesn't have much waveclear, he is an assassin, he is here to kill people, not to split push. That's why he is jungle. If you want to splitpush go AD.
Yes, epic monsters are hard to kill solo, Shaco is not the only jungler that may require help, but he have easier time doing them because of his ult, w.
And, finally, no, tanky bruisers won't enslave you, because you are assassin, you job is to kill carries, not frontline, you can avoid them, that's why you have your Q, R. Even so, Shaco now has more tools to fight tanks - E.
Those were the cons, now let's go back to pros.
- Great counter-jungle potencial.
- Great escape, if played well you are almost unkillable, if you don't get nuked, this is even easier now because of invisibility changes.
- Great ganks.
- He has great presence in map, and if he is not seen for a while, every lane will play differently.
- He is not only a good finisher, but he can also burst carries pretty well.
- His clone and mindgames. This is huge, don't underestimate it.
pretty much is the core on AP 
i play it personally which is why i feel relevant at all with this post, and i can explain the pros and cons as too why its not as good as you think it is.
his W isnt nothing significant with it compared to other AP users who could abuse this further ... 
totally cock blocks any potential all in you could try. Any smart bruiser or tank can easily make you their slave for the rest of the games duration.
+ 
is enough.
- same as Shaco
// 
