The sterling reputation of Sherlock Holmes as a detective is legitimately based upon a combination of a keen ability to reason from observation coupled with a high level of personal energy. Holmes is not above waiting for hours in the dark to catch his culprit, disguising himself for long spans of time in uncomfortable ways, or even living in a rough shelter on a rainy moor so that his client doesn’t know that he is close at hand and observing.
At the same time, it is worth pointing out that Holmes frequently subjects his clients to unnecessary danger, so as to satisfy his own curiosity about the precise nature of the peril they face. In “The Hound of the Baskervilles”, Holmes intentionally uses his client as bait, knowing full well that whatever danger he faces is capable of being fatal, since it already killed an escaped convict. In “The Adventure of the Solitary Cyclist”, Holmes repeatedly exposes his client to an unknown pursuer, who later turns out to be armed. In “The Adventure of the Speckled Band”, Holmes leaves his client in the power of her violent stepfather, who he suspects of having killed her sister (though he does relocate the client on the night when he expects her assassination to occur). In “The Adventure of the Priory School”, Holmes leaves the son of the Duke of Holdernesse with his kidnappers for an unnecessary span of time, so that he can explain the manner in which he located him with maximum drama and in a way that earns him Â£6,000.
All this demonstrates the dangers of choosing a consulting detective who is obsessed with solving the puzzle, potentially at the expense of the welfare and safety of the client. Someone more inclined to precaution and less obsessed with solutions may be a better choice, for those who value their lives more highly than precise answers.
(As a separate criticism, Holmes sometimes allows murderers to go free because he personally approves of the murder they undertook most recently, for instance in “The Adventure of Charles Augustus Milverton” and “The Adventure of the Devil’s Foot”. This may not be so commendable from a public safety standpoint.)