I have given five star reviews to the first three novels in the Malazan series by Steven Erikson, but couldn't bring myself to do so with House of Chains. It was most certainly my least favourite of the series and, although it has some fantastic moments still, it was more difficult to engage with.
One of the reasons for this is that the first part of the novel deals exclusively with a naive but ferocious tribesman called Karsa and his two mates, who rape and pillage for fun. It is hard to see how this will fit in with any of the story we've seen so far in the previous three novels. The 'aha!' moment when I worked this out was one of the better parts of House of Chains.
Another reason is that we encounter the duo of Trull and Onrack - other people have said they really enjoy these characters, but I found their sections rather slow and tiresome.
The novel felt, in general, much slower than the first three I read.
Having said all this, Erikson at not quite his best is still LEAGUES above pretty much any other fantasy writer plying their business these days, and so House of Chains is a far superior novel to much of the dross that can be found on the fantasy shelves. Also, the last third of the book was utterly explosive in many ways and kept me gripped to the last page. I have a feeling that if you've already read three of the novels in the Malazan series, you will not quit at the fourth, but, to anyone who finds themselves flagging, I would urge you to push through. The pay-off is well worth it.