I am a bit partial with regard to this book, as I first read it when I was about ten years old, and I think it was one of the first books to inspire me with my lifelong love of science fiction! Re-reading it many years later, I can see that it has its faults, including some cardboard characters and some dodgy science. But it is still, I think, a powerful read. Colonists living an idyllic life in the Alpha Centauri system are menaced by a fascist-type Earth government, the Galno (Galactic new order) which wants to bring them under control again. The ending is both tragic and hopeful. I would call this book a neglected gem.
I discovered this in my high school library in the early 90s and was very enamoured of it, rereading it several times before I graduated and lost access to it -- until a decade or so ago when it finally occured to me that I could probably find it online! I've reread it once or twice since then, but not recently, and I honestly thought it wouldn't hold up on this reread and I'd say a fond goodbye to it -- but no, for some mysterious reason I still really like this book. Through the power of Google I discovered it's a bunch of 40s novellas that were rewritten into a coherent novel, although it sounds like it was meant to be a novel before it got split up into novellas for magazine publication. The women don't get to do enough, but the misogyny is surprisingly minor given the period in which it was written, and there's cool biological tech and totally unrealistic characterisation, and I love Anstar and Amber, I'm not sure why. I can't exactly recommend it but it's going back onto its shelf.