Don't apologise! I've got the other books from Card in Ender's Saga on hold at the library. There's a looong queue for them.
Miéville's was hard, but rewarding reading. Truly exceptional.
I don't think I am "smart enough" for a Canticle for Liebowitz, but I'm trying.
No wonder. I never got to read the prequel, The Formic Wars, but at some point I might.