I read Arthur C. Clark's novel Childhoods End in High School and from what I recall this television mini series is extremely faithful to the novel and at the same time relevant to the times, considering the book was written in 1953.
I am throughly impressed with this mini series, the effects are outstanding! The Overlords ships are better designed than many Hollywood puts on the silver screen, and when we finally see what Karellen's species looks like it is exactly as I remembered from when I read the novel so many years ago.
Anyone looking for an Independence Day type sci fi show will be sorely disappointed, Childhoods End tackles the subject of first contact with painful honesty and the ending, similarly is certainly not for those expecting humanity to fight the Overlords and drive them away. In fact the story of Childhoods end is a very bittersweet pill to swallow, which if I were to guess would make this mini series not too popular with many....ESPECIALLY Christians!
Childhoods End does not skirt the subject of what becomes of religion once first contact occurs, in fact it pretty much hits it full on, Karellan even confronts Peretta in the second episode telling her her faith is a crutch! That'll definitely piss some people off!
I respect the creators of this show for not diluting the story to appease those who get offended by every damn thing these days.
If you like intelligent sci fi I highly recommend finding the book and checking out this fantastic mini series from SyFy!