The first five episodes were quite absorbing. The acting was excellent by the father, the young son, the daughter, the deaf girl and Timothy Spall, making their characters quite plausible. Keeley Hawes had a difficult part to play convincingly and most of the rest were quite average.
The real let-down was the last episode. My impression was that the playwright/author had no idea how to finish the play with any conviction. A couple of the rather-too-many story lines were quite superfluous and consequently just ran out of steam. The others just were not at all convincing.
By the end , for the first time I can recall, I felt that I had spent 5 hours watching something that really was time wasted. The last episode was truly abysmal and did the previous 5 episodes no justice at all.