Went back and forth a lot on the rating. For the first few chapters after the plot starts (i.e. the titular knaves' wager) the hero reaches a level of smarmy douchebag that was off-putting, but then the book recovers and I really enjoy it the rest of the way through, with him serving up some excellent pining (I am a sucker for a good pine) for the heroine whom I liked very much, and the secondary characters being particularly great.

So...!??!?!? 3.5???/

Numerical scales man. ART IS MORE COMPLICATED THAN THAT.