Trouble was it took a subtle suspenseful novel and turned it into a formulaic and predictable US TV series. It was uninspiring TV wallpaper but in fancy locations. Quality source and cast let down by horrible direction and story adaptation. The best I can say is it wasn't terrible. Nor was it a patch on the old or new BBC adaptations of Tinker Tailor.
I grant that it far from le Carré's best novel, but it was a damn sight better than this!