The Sci Fi novel starts with an slightly alternate history. Back in the 60s the Russians stayed ahead in the space race and actually sent a probe to Venus. Where they beamed back pictures of humans fighting Neanderthals in an earth like environment.
Thats where this story takes off, with the east and west having set up minor settlements on Venus.
The story follows one of the westerners as he greets a new influx of settler/scientists. Then the story moves into adventure. We have an epic voyage, wars, aliens and mysteries.
The story is well written and features constant discovery of new things about this amazing world that keeps the interest level up. The adventure is engaging and the characters seem real enough, so you can follow the plot and really bury yourself in it.
I read this in a couple of days. It was good. :)