What's there to say that others haven't already? It's a well designed game coupled with straight up amazing GM tools. The revised edition only improves upon the already great core.
The on-foot stuff is solid, if nothing special. It's what you would expect from OSR-in-space. The combat is brief and deadly, and best avoided or circumvented somehow. Psykers are pretty cool. The lethality won't work for every group, but the provided "heroic" rules tone it down, while still keeping things quite deadly.
I'm yet to find better mechanics for space combat. SWN gives everyone something to do, and and makes spaceship combat a genuinely tactical and cooperative experience.
Overall - worth getting, and a steal at this price. It's very suitable for sandboxy, exploration campaigns, and even if you decide to use a different system, the stellar system generation tools will still be useful.
[5 of 5 Stars!]