Bean grew up very differently then Ender, he grew up on the streets where starvation was a daily fear. He was unusually small and bright for his age, before being admitted to battle school he changes the way the streets are run, bullies taking care of the little kids where before they would pick on them. He also changes things up in the battle school where he refuses to play the fantasy(mind) game that all of the other kids love, and analyzing the teachers as much as they attempt to analyze him.
I personally enjoyed Ender's Shadow more because I like the character Bean more, his mind set is very different yet very similar to my own. How he processes information, how deliberate all of his actions are. It also shows all of the cracks in Ender's armor how very close he was to breaking and why some of the things that happened in Ender's Game did.
For everyone who enjoyed Ender's Game this is a great story for those of you who haven't it's still great and as they are parallels you don't need to read one to understand the other.