Each book in the Post-Human series isn't very long, or deep, so don't expect a ton of character development here; however, David Simpson does cram a dizzying array of science fiction topics into this small space. The sci-fi concepts include nano-technology, human augmentation, Matrix-like virtual reality, sentient artificial intelligence, Borg-like assimilation, terraforming, and alternate universes just to name a few. The story itself is a wild ride that goes from one mankind threatening scenario to another in rapid succession with hardly a breath in between. It is an over the top action movie in book form with mankind constantly on the brink of extinction as the lead characters battle to save it.
Sub-Human starts with a political climate pitting two sides against each other over the controversy of strong AI. One side believes that if a true artificial intelligence is created it will quickly realize that humans need to go and mankind will face extinction. This faction will stop at nothing to prevent the other side from actually creating such an AI including a nuclear war. Basically, they are willing to destroy human civilization in order to prevent a future AI from doing so.
Post-Human tackles the endless desire to better oneself through technology and the ramifications of doing so. Nano-technology allows Post-Humans to become almost immortal but it comes at a great cost as Post-Humans become dependent on technology for survival. We've all seen enough sci-fi movies to know how that works out and when the technology turns against humanity there is little hope of survival.
Trans-Human finds mankind facing a threat from beyond the solar system as old enemies become allies in order to survive this new external threat. It turns out that Earth isn't the only planet to have evolved to a human vs machine armageddon scenario and alien visitors are here to help in the conflict - but which side are they on?
Human Plus is a weird one and any attempt to explain it would be a potential spoiler so all I will say is that it was my least favorite book of the series. You don't really know what is going on in this one until the reveal at the end.
Those first 4 books can be picked up together in one compendium on both Kindle and in audiobook format and that helps to overcome how short each book actually is and gives you more story for your money.
The fifth book, Inhuman, reveals a new uber evil that has been lurking in the background the whole time and it changes your perspective on what has gone on so far. It maintains the fast pace of the series and sets the stage for more.
Overall I found the series enjoyable but there are times where the fiction dominates the science a bit too much and some laughable explanations are given for why technological things work the way they do. I found that I was able to look beyond those times and just went along for the ride. If you are looking for something deep and profound then you should look elsewhere, but if you just want to gorge yourself at a fast paced sci-fi buffet then you have come to the right place.
Ray Chase does a decent job at the voices of the various characters for the audiobook and while his performance wasn't perfect I thought he did a good job on the narration.