Despite how phenomenal Beauvais' artwork is, I think Nightmare Asylum the novel is just much better. It puts more onto the success of the characters, rather than how incidental it felt in the comic. I think Spears is much more interesting fleshed out in there (I know you disagree HuDa).
And Female War is much more improved to, especially with the lack of Keith's artwork. Though I still f**king hate that little romance sub-plot between Wilks and Billie. I do think Outbreak/Book One/Earth Hive is about on par in both though.
Genocide I really enjoyed the novel, more so than the comic.