I recently re-watched The Iron Lady. I gotta say, I really like having different actors playing the same character. I suppose Meryl Streep was more accurate in her portrayal of Margaret Thatcher. And I think that film was an honest look at Thatcher's life, almost to the level of being a docudrama.
That said, I am posting in the Tabloids thread because The Crown is an expensive, live-action tabloid. And Gillian Anderson gave us a fictionalized, tabloidish version of Thatcher. Except for the tilted-head thing, I really enjoyed her "extra" portrayal.