When he is good, he is very, very good.... when he is not-so-good, he is horrid. Not the writing, the subject matter--some of which is, after all, horrid.
On balance, it's 2-and-a-bit; but since it's Neil Gaiman, it gets three stars.
My favorites are:
A Study in Emerald
October in the Chair
Good Boys Deserve Favors