I tried watching but I couldn't stand it. I know it's not a documentary but it's littered with basic errors. For instance, the doctor coming in to tell King George VI the truth about his health (in reality it wasn't spelled out to him and at the time of his death he thought he was getting better) just came into the room and sat in front of the King at his desk without being asked to sit. Even today that would just be a 'No,No'. In 2016 visiting PMs from the Commonwealth sometimes chat standing to Elizabeth until the Queen indicates a chair.
Plus, the voices aren't right. The Queen especially had a distinctive voice as a young woman, high pitched and very upper-class, naturally! Not only the female lead but others had difficulty maintaining the accent of the time, it seemed to be worse among the younger female actors. It's not entirely their fault, those cut glass tones just haven't been taught at drama schools for about fifty years. You hear struggles with it in other period dramas and Agatha Christie dramas as well.
Also, couldn't they have got a less robust looking man to play King George VI? The King was notably frail by the late 1940's. He was looking as if 'he walked with death' as Churchill later said. Several of the actors didn't look right. Margaret was beautiful as a teen, with lovely eyes. The actress who played her was drab. The actress who was Clemmie Churchill had a short curly modern haircut. What was going on there? Didn't anyone on production ever take a look at docos of the time showing Mrs Churchill with a rolled up bun style at the back?
There was so much of this I just can't detail it all. It just jarred on me. I won't be watching any more.