Well made and acted but I'm afraid it didn't have the guts to show the reality of the result of their treason. Why did we not see the suffering and death of the agents whom the Cambridge spies betrayed? Why did they never confront the hypocrisy of helping a regime which sides with Hitler, imprisons its' population and regularly executes their KGB contact agents? It tries to be sympathetic to men who put their loyalty to their friends above their loyalty to their country, their colleagues and those they're supposed to be protecting. What's more even that is incredibly flawed, Blunt abandons the rest of the group to their fate, Philby sleeps with McClean's wife and sends Burgess to accompany him into exile behind the Iron Curtain unaware that he's never coming back to the UK (and will quickly drink himself to death in Moscow).
What's more it only seems to tell half the story, concentrating disproportionately on the recruitment process and the influence of the Spanish civil war on the group. We get none of the fallout from the defection which was a revelation in Britain at the time or Philby's infamous press conference which is still cited today as a classic example of how to lie, we never get Philby's flight from Beruit or McClean and Caincross' plea bargain. Perhaps the most sympathetic character in the whole story is James Jesus Angleton who appears to be the lone voice in the wilderness.
So all told a great series but do some research first.
