The one exception is a dreadful one. Here's Holmes' brother Mycroft as described on Wikipedia:
Possessing inductive powers exceeding even those of his younger brother, Mycroft is nevertheless incapable of performing detective work similar to that of Sherlock as he is unwilling to put in the physical effort necessary to bring cases to their conclusions.
...he has no ambition and no energy. He will not even go out of his way to verify his own solutions, and would rather be considered wrong than take the trouble to prove himself right. Again and again I have taken a problem to him, and have received an explanation which has afterwards proved to be the correct one. And yet he was absolutely incapable of working out the practical points...
—Sherlock Holmes, speaking of his brother in "The Adventure of the Greek Interpreter"
Though Sherlock initially tells Watson that Mycroft audits books for some government departments, he later reveals that Mycroft's true role is more substantial. While Conan Doyle's stories leave unclear what Mycroft Holmes' exact position is in the British government, Sherlock Holmes says that "Occasionally he is the British government [...] the most indispensable man in the country." He apparently serves as a sort of human computer:
The conclusions of every department are passed to him, and he is the central exchange, the clearinghouse, which makes out the balance. All other men are specialists, but his specialism is omniscience.
—"The Bruce-Partington Plans
That contrasts with the modern Sherlock, whose brother is a covert, powerful, active mover and shaker inside the British government. And in the classic tale, the two get along well. In the modern adaptation, they clash constantly.
I wondered if the BBC would continue to produce episodes and they have. There'll be three coming to the U.S., starting in Seattle on the evening of Sunday, May 6 and continuing on May 13 and May 20.
If you get the chance, you might check your local times and watch them. If the second set is as good at the first, they provide a good illustration of adapting a classic tale to contemporary times.
--Michael W. Perry, Untangling Tolkien