Shemeska said:
*ponders* How does it compare to Hellbound?
It doesn't, really. The writeups are just there to allow you to incorporate Tanar'ri/Baatezu armies into your battlefield in smaller units, basically it's like "Command Retinue is made up of demon/devil type x, who upon attack will use round-by-round-tactics y", "Scouting forces are made out of demon/devil type z, who will ..." et cetera. No "large scale" fiendish tactics or plots - anything that made Hellbound what it is.
BUT:
It's an excellent start for you to make up units from scratch using the HoB system, as they discuss various army concepts at length (for example, the differences between feudal and modern armies, different tasks and concepts). Thus, using the existing monsters, you'll quickly be able to group them according to their task on a battlefield. Even though the idea isn't that new at all, for me it is a great font of ideas (well, but then again, I'm no military nut

). I've been using it for a Blood War battle scene with no problems; if you want to run a large scale battle without wanting to roll a million dice, HoB really helps you organize and thus to cut down prep time.
I didn't have any preconceptions nor expectations on this book before it came out, so it's really up to folks' reviews or suggestions whether I even glance at it, let alone buy it. I'm curious if it's worth my $30.
Well, I don't know if you picked up Champions of Ruin after all

but after flipping through CoR and reading HoB cover to cover, HoB comes out on top. I'd give it a 4/5 score. It really could have been even more in-depth if they'd given it another 50 pages, but even so, it's a good book - and since the art manages to have not a single weak piece, I feel the price is justified. If you want more opinions, I think there's already a thread floating around here somewhere with various people discussion HoB vs. mass battle systems - I've posted my reasoning
there.