At Ferretbrain, Arthur has a truly epic (by which I mean "longer than 20,000 words") look at the Conan stories. His conclusion:
Do I sometimes find my blood racing when I read the Conan stories? Of course I do. But I can usually count on Howard to say something awful and completely ruin my enjoyment sooner rather than later. Birth of a Nation was also a stirring, exciting story which got people's blood racing but if you aren't able to recognise how awful it is then something is deeply, deeply wrong. Film students are capable of studying that film, and for that matter Triumph of the Will, and recognise the technical accomplishments and novel approaches to filmmaking expressed therein and which are used regularly in movie-making up to the present, whilst at the same time separating the craft from the content and acknowledging that the content itself is abhorrent. Too many fantasy readers are unwilling to do that. Should we censor Howard? It's a little late for that. But we can at least stop celebrating him.