If I had wanted a documentary about Bletchley Park during WW2, I would have bought one of several good titles available, or a DVD if there was one.
Want I wanted, and got, was a really good fictional account set around the code breaking activities of that centre. The story is loosely based on real characters and events, but it is a STORY, and a very enjoyably told and terrifically acted one. I like all the actors, they work well together. The story is plausible, but I'm not interested in 'is this or that detail correct', I just want a good hour or two of entertainment set in the period of WW2, around that unique institution, and I was well satisfied.
I cannot understand why people have to nitpick. Its not as if anyone is deliberately setting out to 'distort history'; there's no harm in giving a little fictional leeway here and there. The main thrust of the story is sound, and enjoyably told, so 5 stars.