[40k] Horus Heresy novels?

Just finished reading the "Horus Rising" novel by Dan Abnett.

I thought it quite interesting, along the lines of those books Frank
Herbert's son wrote (House Harkonnen etc). I would do a book review,
but I don't feel qualified (I'll leave that for Mr. Bowles or similar:)
I will say that reading along I could begin to understand "where all
this is going", like reading the memoirs of Confederates prior to the
US Civil War.

I'm curious to what you guys have to say about it...