Here's my beef with Ender's Shadow.
To avoid spoilers, stop reading now.
So basically, they make out Bean to be an intellect of astounding magnitude, surpassing even Ender--- uh, what? What I liked about Ender was his empathy; his "emotional IQ", if you will, was a big part of his genius, and ultimately what allowed him to win the Bugger War.
Bean, with his background of emotional deprivation, just doesn't have the skills or the temperament necessary to deliver the final, crushing blow to the Buggers. Yet Ender's Shadow seems to tell us that the Battle School people actually had more faith in Bean than Ender.
It was a good book, written to Card's typically high standards, but ultimately unnecessary. It indulged in what is, in my opionion, the ultimate sin for any multivolume work in any medium: That of retroactive continuity.