Old Man's War was my first Scalzi book but won't be my last! It has a great balance of humour and more reflective moments - sometimes both at once. There are a lot of themes that aren't fully explored yet but knowing that this is just the first in a series I have faith that they'll be examined in more detail as the story progresses. 

I don't think it's reasonable to expect multiple fully-fleshed-out ethical issues in a single novel, and the plot does raise a number of them. I do think the text drops hints as to the various issues without handholding, which I prefer but may be missed by others,

The worldbuilding is done in a very natural way, setting up the pieces both for this book and the rest of the series. I loved the concept of the

consciousness-transferring

tech, which reminded me a lot of

Soma

. The reveal towards the end about the nature of the

Ghost Brigades

is great as it feels like a nice twist while also being obvious in hindsight.

Recommended for any sci-fi fan but if you enjoy thinking about issues like transhumanism, colonisation and space exploration you'll find a lot to get your teeth into!