I just finished reading Ian C Esslemont's "A Night of Knives", which is set in the Malazan Empire. Esslemont is the co-creator of the world but the other creator, Steven Erikson, has already written several huge novels in this series. Erikson's novels are excellent and thus Esslemont's work invites comparison.
You may have noticed that I very recently posted about another book I just finished reading. This is not a coincidence: A Night of Knives is a very short work. This is very obvious when you look at the trade-paperback; it's a tiny sliver compared to the huge tomes Erikson writes. For the regular paperback the publishers decided to use thick paper, large print and wide margins to make the book fatter. Frankly I wish they hadn't, as this just makes it bulkier for no good reason. So be warned: it is a short read.
Aside from the length, I don't have much to complain about. This book is well written; you can tell it isn't written by Erikson but Esslemont's writing style is decent. The only thing that annoyed me about the book was the way the story seemed simultaneously written for people who'd never read Malazan and for people who'd read all of Erikson's works. Basically I found some things under-explained and some things over-explained. Given that it'd been almost 10 years since the first Malazan book came out, I think a certain familiarity with the world could be expected, and thus certain aspects (such as the magic) didn't need to be so "mysterious". We already know how it works! On the other hand, for new readers certain story points could have used more explanation.
Overall the book is a good addition to the Malazan world. It may be better if a new reader reads it part way through the Erikson series; somewhere between books 1 and 2 or 2 and 3 would be ideal. Otherwise the book doesn't really advance Erikson's plot at all, but rather explains some back story. The story is interesting on its own but not crucial to your enjoyment of the main books. (Sorry Ian; you may be co-creator but you're late to the writing party... your book is an accessory).