That reminds me, I'd been going to comment in this thread :)

I really like The Hallowed Hunt - it extends the worldbuilding in a really interesting direction, and the characters are great (but I know that I'm in a real minority on that one...)

I think you could read the Ivan book without having read Cryoburn, as it is set well before Cryoburn.

I'm not quite sure what you mean by heter-oise - especially as it seems to me that only fandom ever considered Ivan non heterosexual...