I enjoyed this story, though I'm always a bit sad to think of Holmes or Watson outliving each other (it's given away on the book jacket).
The book contains minor spoilers for ACD canon.
I like the idea that you can tell a lot about a person by the art in their home. I was amused that apparently what you can tell about Holmes is that he can't be bothered to put up his own art and he just lives with whatever was there before.
I was less pleased by the notion that Holmes is better at everything including medicine. Watson is, after all, a doctor. Being bested there just smacks of the "Watson is stupid" problem which sometimes crops up in Homles fanon. If Watson was really stupid there's no way Holmes would keep him around, desire for an audience or no.
It was nice to see a little bit of Watson showing Lestrade as being not as one dimensional and useless as he's sometimes portrayed in ACD canon.