This is a novel that’s that rare bird, believable space opera. Now, space opera by its very nature stretches belief, but even the fictional viability of the genre has been stretched in later years by that fell beast, the Singularity. Basically, the Singularity meme posits that sure, if we uploaded our minds into computers we might be able to solve the problem of faster-than-light travel etc, but we’ll probably no longer be human.
Williams neatly sidesteps the issue by creating an alien race,the Shaa, who subjugate all other intelligent species within reach of wormholes. They then keep everyone on pseudo-feudal societal stasis for a few thousand years, which lets the author provide his heroes with that space operatic staple, the quasi-Napoleonic navy. They also ruthlessly proscribe artificial intelligence, thus keeping the Singularity at bay.
Naturally, we plucky Earthmen lead the eventual rebellion against those pesky collectivist Naxids, who attempt to take over after the Shaa and basically kill everyone.
All in all, a hugely enjoyable read within its genre.