More like 3.5 stars.

1. Long for a crime novel, but I was never bored. It's a fun mystery with quirky, memorable characters, and I wanted to know what happened to them.
2. It's light on urgency, suspense, and danger. This is not a tense thriller, but it is a tightly plotted mystery.
3. It has a good solution - surprising, makes sense, satisfying - but it takes the detective so many pages to explain the solution that I think the known facts aren't sufficient to reach the given solution.
4. A subplot regarding the detective's assistant's personal life is never resolved. Are there going to be more of these books? (UPDATE: Apparently yes.)