The Book and the Screen

What do you think about film and television adaptations of books? I'm re-watching the new Sherlock on Netflix and enjoying myself so thoroughly, yet again, while doing so. I do love to read the stories but I also heard the TV miniseries creator saying on a radio interview that the Sherlock Holmes stories were, in a sense, the first television scripts. They were each written to stand on their own, like and episode of TV, but had a few narrative threads connecting them from one story to the next. So you could pick up along the way if that's what happened, or from beginning to end.

Then there are the other mysteries turned into miniseries, mostly featured on Masterpiece Mystery, like Wallander, Miss Marple and Inspector Poirot. I think they're awesome, especially how they're remade over and over with fresh twists and slight changes in characters. What do you think? Is it a degradation of literature to have Jane Austen and Agatha Christie miniseries or exactly the right thing for bringing new life to dear old beloved texts? If the remake's done well, I love the heck out of them.