If you’ve read the books — are they following the story pretty closely?

No, they fucked it (I loved the books). The cast is good, but some of the deviations are too stupid for words. Namely,

spoiler

the mysterious high-tech whirr-sounding entrance to the AI datacenter with a generated voice somewhere at the bottom of the Silo in S02E09 made me turn the series off in disgust and I am NOT RETURNING

. How stupid are they prepared to have their screenplay to inject the current thing? There's no bottom apparently.