Ian Carmichael is one of the best readers I've come across. If you've seen him as Lord Peter Wimsey on TV and been, shall we say, ambivalent about his portrayal, don't let that turn you away from the audiotapes. On tape, Mr. Carmichael catches the essence of Peter Wimsey: the quick, light speech; the self-aware mockery; sensitivity covered up by quotations and babbling.
Unnatural Death has always been one of my favorite Sayers (and also has one of the most fabulous last lines in popular fiction). In Unnatural Death, you get a hefty dose of Ms Climpson, a pro-active Parker and vignettes of village life (something that Sayers does very well). The plot is a tad convoluted (there are some points I still puzzle over), but psychologically, the murders all make sense.
One of her earlier novels, Unnatural Death does not delve as deeply into morality or characterization as some of Sayers' later works. But it is still a satisfying listen that is more than a mere puzzle.