This is a terrible adaptation of a fantastic book. Within 5-10 minutes I wanted to turn it off but persevered to give it the benefit of the doubt (which was not worth doing).
The adaptation bears no similarity to the book. I can understand some slight artistic changes but this completely changes key plotline and characters. It opens on the death of David's father but he plays a key role throughout the novel as a wise elder and a contrast of the previous generation showing the Hartley's rapid rise to wealth. Grace returns with David from Birmingham, rather than his leaving her in the village while he goes to Birmingham. And their relationship is far more nuanced and complex in the book with Grace having clear disdain at times for David while also accepting he has changed her life for the better. Why bother doing an adaptation if you change the core of the plot?
As others have commented, the dialogue/script is terrible. The improvisation is as awkward and stilted as a Year 6 play. The scene at the wake where characters repeatedly say the same thing to David is more like a scene from Love Island than a BBC Drama.
The first episode ekes out what could have been achieved in the first five minutes over 65 minutes. I assume this will be stretched unnecessarily over 7 seasons like Peaky Blinders.