A short read. Not bad but not amazing (for my tastes).
I wonder how much I would I have enjoyed it more if I hadn't watched the modern Sherlock episode that's loosely based on it. It was very loose but enough was similar that some key points were "spoiled".
The structure is odd by modern day standards I think. A book of two halves. The first contains the crime and the chase and capture of the perpetrator. The second contains mainly back-story and then a double denouement - the perp telling us why/how he did it and Holmes how he figured it out. These days that would be one narrative. Also to wait half a book from "we got him" to that explanation of what happened, I don't think would be done now.
Well at least I can say I've read some Sherlock Holmes now, but I don't feel the need to read any more.