Bottom line: I enjoyed it.
Nova's two-hour dramatic special on Charles Darwin starring Henry Ian Cusick wasn't that bad. OK, so the look of the film wasn't precisely correct (that was obviously not Down House, and Darwin was bald by the time he started work on Origin), but the film was generally pretty accurate, not too melodramatic, and filled with delightful little bits from the life of Darwin that it was hard to resist liking it.
The basic storyline follows Darwin in 1858 as he's working on his "big book" to be called Natural Selection. A letter from Alfred Russel Wallace arrives, describing a theory of speciation by natural selection that according to Darwin is nearly identical to his own. In despair, he confides the story of the development of his theory to his wife Emma, which leads to lots of flashbacks of adventures on the Beagle, meetings with such luminaries as Charles Lyell, Joseph Dalton Hooker, and John Gould, and experiments around Down House. Meanwhile, Charles and Emma deal with the (eventually fatal) illness of their baby Charles Waring, and Hooker and Lyell arrange for Darwin and Wallace to receive joint recognition at the Linnean Society. The ongoing conversation with Emma, wherein Darwin explained everything about his theory, seemed forced and corny at times, but their conversations were at least accurate reflections of attitudes they probably had (even if they were never actually spoken).
You can watch the film for free online at pbs.org, or you can pre-order the DVD or Blu-Ray at Amazon.com.