Warning: minor spoilers present.
I thought the premise behind this collection was excellent, and looked forward to reading the contents, but it has to be said that the stories vary tremendously in quality. The Kindle edition is mostly good, and illustrations do appear among the text, but there are some formatting errors.
The book itself begins well with an interesting introduction, 'Ghosts May Apply' by David Stuart Davies (who has written some excellent Holmesian stories himself - none of which appear in this book). This surveys the more fantastical work of Conan Doyle as well as his Holmes tales, and gives an informative overview of the ghost detectives who became so popular around the time of Sherlock's success. Sadly it is marred by a glaring textual error at the end.
A second introduction follows: 'An Introductory Rumination on Stories for Which the World is Not Yet Prepared', by Charles V Prepolec. The title doesn't bode well in its pomposity, but it isn't all that bad, being a more personal survey of the influences on the editor himself. After this we get down to the actual stories.
1: The Lost Boy, by Barbara Hambly. This is a quite entertaining fantasy which unites Sherlock with Peter Pan in an adventure which has no relevance whatever to the detective tales of Doyle. Well written, all the same.
2: His Last Arrow, by Christopher Sequeira. A somewhat bizarre effort, competently written but with an atrociously poor concept and plot which reimagines Watson as a glory-seeking idiot and Holmes as a sadistic monster.
3: The Things That Shall Come Upon Them, by Barbara Roden. One of the best in the collection, a fascinating pastiche which has Holmes and the more occult Flaxman Low dealing with the aftermath of M R James' legendary tale 'Casting the Runes'.
4: The Finishing Stroke, by M J Elliott. By contrast, one of the worst in the lot - poorly written, by someone who shows little idea of the Holmes canon, and the ending is absurdly far-fetched.
5: Sherlock Holmes in the Lost World, by Martin Powell. Very clumsily written indeed; verbose, ungrammatical, and again showing no real understanding of the characters and settings it borrows. The dialogue given to Lord John Roxton is so bad it is actually offensive.
6: The Grantchester Grimoire, by Chico Kidd and Rick Kennett. In this Holmes is put onto the same case as Carnacki the ghost hunter. It is not badly written and the plot is tolerable, but it is rather predictable.
7: The Steamship Friesland, by Peter Calamai. A lame effort in which Holmes discovers he has mediumistic powers and comes to the aid of a ghost.
8: The Entwined, by J R Campbell. A very poor story in terms of plot and characterisation, but at least written by someone with a good grasp of grammar and diction.
9: Merridew of Abominable Memory, by Chris Roberson. Pompous, predictable, and unnecessarily gory.
10: Red Sunset, by Bob Madison. Reasonably entertaining piece which has Holmes and a hard-boiled American detective facing Dracula.
11: The Red Planet League, by Kim Newman. This is the best story of them all, in spite of the fact that Holmes doesn't even get a mention in it. A very funny and sharp tale of Professor Moriarty's revenge on a scientific rival, as always laced by Newman with extremely well-informed references to period pop culture.
So for the money you get two excellent stories, two pretty good ones, one tolerable and six poor to awful ones. Personally I thought it was worth the price just for the Newman and Roden stories, but then I paid less than £2 for the collection; I would not have been happy had I paid more.