TLDR; This was a pretty good book for someone to read while they're waiting for the next Vlad Taltos book from Steven Brust.
This was recommended as a good example of "comic fantasy." It's certainly lighthearted for the most part, although keeping that tone in the context of a murder investigation and an impending war and siege is an uphill battle, and one that doesn't completely succeed. There's a blurb on the front cover-- "blindingly funny." It turns out that this is actually an excerpt from a review of a different book in the same series, which is a practice I've always found distasteful and vaguely fraudulent. I have not read that particular book-- maybe it's "blindingly funny." This one wasn't. Vaguely amusing, sure. Laugh-out-loud funny? No. Blindingly? Not hardly.
I also found the protagonist profoundly unlikable. Maybe I was supposed to? I'm not sure. But it kind of said something that this ex-soldier turned private investigator was much less appealing than Brust's assassin. I think it might have been the particular choices of "amusing foible" used to characterize Thraxas-- just as an example, misogyny played for comic effect is still misogyny. It's 2015, guys (ok, 2007 when it was written). Having the "good guy" in a work espouse a position lends weight to the position, especially if he does not actually suffer for the espousal. Saying, "Oh ha ha isn't he a jerk" does not actually excuse him being a jerk.