Acacia is a novel which is epic in the broadest sense of the word, concerning the shattering and building of empires, across a large scale of time, and centred around a relatively small key cast of characters.
It is in this first area that Acacia does best. The world which David Durham has created is intricate, fascinating, and lovingly presented. The gradual revelation of each area of that world is handled well, and the reader is left breathless from the sense of grandeur and scope, and impressed by the background which interweaves each of the disparate cultures that are presented.
The book is written across a large piece of internal time; that time is not all present in the novel. The characters we will follow are introduced in the first half of the novel, and their fates left undecided - the reader is then re-introduced to those characters some years later. I enjoyed the abrupt nature of this change, exploring what were familiar characters, and reorienting my expectations from the character's actions, and the hints of their `missing time' gleaned from their interactions with others. On the other hand, some people may find this sudden jump in continuity more jarring than refreshing.
The characters are at once the greatest strength and weakness of the text. Each character within a faction has their own motives, and, as mentioned in other reviews, each faction of characters has their own point of view - Durham allows the reader to feel sympathy for one set of characters, and then swings to another viewpoint, and establishes your sympathy with those (often adversarial) characters instead. While some characters are less ethical than others, each has a valid point of view, and Durham tries hard to get us to understand it.
This `shades of grey' characterisation is one of the strengths of the book. Unfortunately, it feels as if the individual characters (as opposed to the factions, or groups of characters) are a little shallow. While some have their motives expressed in detail, others seem to remain question marks throughout the book. Perhaps that will change in later novels, but it is sometimes difficult to empathise with a character about whom we are shown or told a great deal, but not given much access to their personal motivations.
Having said that, the key characters are well written and represented, and while they may seem to play second fiddle to the world around them, that world is so rich that it may not matter. Throw in a plot which is reasonably deep and complex, with a few sharp twists and turns to throw off standard fantasy tropes, and this is an excellent novel. Highly recommended.