Okay so how the hell could madara kamui himself so fast I mean he is a jinchuurki so he should've been much slower and obito was only just this fast when both Kakashi and himself used it on him, this is complete bullshit
Madara has been using MS/EMS for the longest time period (a lot longer than anyone else). He probably had enough experience to immediately activate MS and use kamui.
The only thing is how he can do it if he is a Juubi-jin? Although that was never explained well anyway.