Having re-read the book(s) some 30 years after my first reading, they hold up really well (this version of 1888744] is actually an omnibus edition of the first two volumes of the series, [b:1888744] and [b:Galactic Derelict).
It holds up fairly well - there are few anachronisms introduced by the advance of technology since Norton wrote the stories, but there are a few strange quirks of technology. Why is a refueling station still operative (barely) thousands of years after its abandonment, but the components that store the memory of spaceship navigation are so fragile that they have to worry about even new ones? If your ship's navigation is broken, you're doomed. If the refueler breaks, you call out a repair crew: it doesn't need to be nearly so durable.
That said, the characters are enjoyable and mostly believable; the technology is not inconceivable; and the plot works. The stories are still, after 50 or 60 years enjoyable enough that now I'll have to read the sequels - which I haven't read before.