Childhood's End has some fascinating problems.
First off, it's beautiful. It's beautifully shot, the effects are amazing, and the acting is excellent. Charles Dance can command any scene...even when he's not in it.
So here's the problem. The first episode opens up with a brief text commentary about how Arthur C. Clark changed sci-fi forever when he wrote the book in 1954. It goes on to say how the book has influenced just about every sci-fi show every made. So they're hanging a lampshade, from the first step, on the fact that we've seen every trope in Childhood's End 1001 times.
This weird sort of back-handed apology does not play well when the tropes start up right away. But...okay, I can get over that. They're being loyal to some classic silver age sci-fi, bravo. Good for them.
But then they play with each trope by going super meta. Someone at the newspaper wants to call the aliens "The Visitors," when the ships first show up one of our heroes is watching the scene from the BSG miniseries where the Galactica and her fleet make a desperate escape from the Ragnar nebula. Again and again, we're very subtly reminded of what the opening text told us -- you've seen all this before.
In which case, in the era of nothing but sci-fi and genre television, why am I watching it?
There are also some bizarre editing choices that leave you perplexed during pivotal scenes. The story feels trimmed and forced. The goodnik farmer boy is the speaker of the world bang-boom-done. The cynicism of the newspaper folks has to be carefully explained, and becomes clumsy. Why are they cynical? Because they think this is actually an invasion. Explain, explain, belabor, explain. You don't need to hold our hands here guys because...um...we've seen all this before!
Oh well. I'll tough out the three night event. I sat through Ascension, after all, and that was like dental surgery.