storm of iron & the iron warriors books are ok. They do suffer a bit from the "evil for evil's sake" problem, but at least the editing isn't terrible.
If you want chaos books I would recommend (in no particular order):
ADB's night lords series
Storm of Iron *and subsequent stories
Lord of the Night
Blood Gorgons is pretty good
from the HH series:
Flight of the Eisenstien
Legion (kinda... not really chaos-y)
In general, when looking at Black Library you can bet that anything by ADB & Dan Abnett will be a godo read. Full of CHARACTER, exciting battles, and just solid story construction. Up until recently DA was my favourite author due to the Gaunt's Ghosts series, but I would put ADB up above him - I find DA stories seem to wrap up nice & clean & frequently with a bit of Deus ex Machina (which is ok sometimse... but not all the time...). that being said, both authors are top quality (though I have a friend who just full-stop hates anything by black library... same friend recommended hunger games to me so there's no accounting for taste I guess...)
Black library has many good authors, many poor authors and the two I mentioned above are fantastic. I typically don't read anything by any other BL author, I've been disapointed too many times. I describe my love affair with BL books as "battered wife syndrome" - with each new book release I promise myself that "it can't be as bad as it was last time! Surely they know how they hurt me & are going to be better now!" But it is so rarely the case. NOTE this is especially true with the WB novel series...
Again, I only have (2) complaints with the WB series, the first is fully at the hands of the author - that is the evil for evil's sake bit. The 2nd is shared between the author & editor... But so much of the printed works delivered by GW are flawed - spelling errors in rulebooks, IA books & novels.... They really need to examine their editing team...