I think I've read all of the "canon" of Sherlock Holmes - Arthur Conan Doyle's short stories and novels - as well as many of the derivative works like The Seven Percent Solution
and Laurie R. King's Mary Russell series, and of course over the years I've watched many of the Sherlock Holmes movies, like the ones from the '40s with Basil Rathbone, and the Jeremy Brett portrayal from 1980s-'90s TV. Of those various productions, Lyndsay Faye's treatment in Dust and Shadow
stands out as among those most true to Doyle's characters.
Faye's Holmes is portrayed much as Doyle himself did - as a rather eccentric, secretive, brilliant and frequently arrogant man of some means, who nonetheless is able to easily alter his outward appearance and manner to fit in with any social class. These skills serve him well in this novel, as in many of the original stories - Holmes infiltrates the seamy society of the back alleys of Victorian London and uses the information he gathers there to unravel the mystery of the Jack the Ripper murders.
This is not the first time an author has looked into the question of how Holmes would have fared against Jack the Ripper - and like most of the other works that have examined the Ripper case, it uncovers the Ripper's identity, but concludes that the answer must be kept from the public. Faye's version not only stays true to the Holmes mythology, but her outcome is a plausible explanation for the Ripper murders as well.