I've just finished re-reading Le Carre's book on which this is based, so I was interested to see what the Beeb would make of it. Less complicated than the book, moved in time and moved to Zermatt, but very good.
A spot of googling brought me to an article in the Indie, by Jack Shepherd (not the Wycliffe bloke), talking to Le Carre, with the sub heading "Why not write your own bl**dy novel? With all those changes, what’s left of mine?", which at first sight leads you to think Le Carre didn't like the adaptation. However, the full text from the article is:
The BBC adaptation will also have a female protagonist instead of male: “To all of which, a lesser being such as myself might reasonably have responded: why not write your own bl**dy novel? With all those changes, what’s left of mine?
His verdict? “And the answer, surprisingly, is: a great deal is left, more than I dared hope.”
So he likes it too. Sub editors, eh?
Mind you, Jeds, in my head, is a whole lot sexier than Elizabeth Debicki.