There were two stories in the edition I read. The Strange Case of Dr. Jekyll and Mr. Hyde, and the Weir of Hermiston.
They both get three stars from me. I confess I was a little disappointed with Jekyll and Hyde. I'd never read it before, but was familiar with the basic premise of the story. Stevenson could have done so much more with this concept. The whole thing was very abrupt, moving from the opening mystery to each new revelation with such rapidity that I barely had a chance to enjoy the process of discovery. He could have given it so much life and excitement throughout, but he left it limp and devoid of flavor. Pretty ironic how it could be both fast and lifeless. I know he meant it more as a commentary on the duality of man's nature than as an entertaining piece of fiction, but I was still disappointed.
The Weir of Hermiston was the piece he was working on when he died, and so it is incomplete. He did have some idea of where the story would go, which he shared with some relatives. This book included a brief synopsis of his intended plot for the story. And I think that had he lived to finish it, it could have been a really compelling story. I do have a couple issues, though. The first is that he tells the story mostly in long narratives. Not very interesting to read. The second is that when he does use dialogue, he writes it using the phonetics of the lower-class Scottish accent. I could understand 90% of it, but I think I missed a few key points along the way. Again, I think if he had lived to finish it, he might have been able to work those flaws out of the book.
With less than 200 pages combined for both stories, it took me all month to work my way through. It was interesting enough to persist, but I found I could only focus for short periods on either story.