Enough negativity, I enjoyed Red Harvest though I'm pretty sure it requires quite a suspension of disbelief. Is it really possible for some guy to wander into a town called Personwood (or is it Poisonwood?) and then basically swap siides whenever he feels like it from one gang to another including the police, leaving behind him a trail of bodies that makes you wonder if there can be anyone at all left alive to arrest.
On the other hand, Hammet was some kind of private eye I believe so I guess he knows a hell of a lot more about it than me - or Chandler, though from what what I've read (and seen) I do prefer Chandler.
Red Harvest has been adapted several times I reckon, thing is, some of the films that say they are based on it seem to have relatively little to do with the book whereas there are several films (eg that one with Bruce Willis and Christopher Walken) which are pretty much identical, but which, at least when they out didn't even acknowledge the influence.
ps Dashiell is a strange name, if I recall correctly it was an adaptation of his mother's surname, she was of French descent and I think she was called De Chiele of something like. Interesting tidbit for you iff you ever find yourself in a pub quiz in which mobile phones are allowed. Although I probably misspelled it so you will get it wrong anyway.