I did not have any immediate problems with the events or how they played out. It was enjoyable for the most part but I did find the timing of it a bit off. Having a flashback that is over a volume long just as the Arrancar invade the world of the living was a bit jarring.
I also find it strange that Urahara, Yoruichi and Shinji for all of their wits, could not warn the 13 Court Guard Companies about Aizen for over a century or that Gin did not turn any of this to his advantage in regards to betraying Aizen.