John Le Carré's Africa is a very different place from Alexander McCall Smith's. The book is set in Kenya, with endemic poverty, sickness, corruption and collusion. Beginning with the murder of a white activist who just happens to be a British diplomat's wife, the book charts the unravelling of lives, the murky world of the global pharmaceutical corporations, and the tradeoffs between convenience and conviction. It's well written, though you do need to be tolerant of JFK or X-Files-style corporate conspiracy theory. For the most part it's plausible, though some of the technological problems that beset Justin Quayle while reading the contents of his wife's laptop seem unlikely, and some of the heavies that are dispatched to deal with him are clumsy in a momentarily comic way.
I'd heard mixed views about this book, but decided to try it for myself. Interestingly, chatting to my father over Christmas, he said he thought Le Carré had lost it a bit since the end of the Cold War, and that his recent stuff wasn't nearly as good as the Smiley books. I'm not so sure; he's writing contemporary fiction, and there is no Cold War any more. Le Carré is a very convincing angry old man in this book: the "Author's Note" in epilogue is particularly chilling for the acknowlegdements he makes to people he will not name.