First: 
 What really sets Raymond Chandler apart from his precursors and endless successors is the microscopically-trained eye for detail (obviously an asset in detection) and ability to convey it in concise, exacting terms. I could draw his sets and characters from memory. And, of course, his narratives are gripping, but then it takes an awfully sorry noir to be actually boring. 
 ... 
 Then, finished: 
 This was my second foray into Chandler, and maintains my earlier impression that he's at the very top of classic noir. His strengths remain soundly his strengths (crisp, refined prose and sharply-drawn cast), and while this isn't quite so elegantly plotted as the Big Sleep, he's actually reigned in a few less admirable tendencies: Marlowe shows flickers of greater depth and compassion behind his deadpanning, and the female cast here seems more sympathetically and fully developed. Plenty of mercenary motives and ethical failings, of course, but that's just Chandler's L.A.; the females here are often a sorry lot, but I'd hazard to say no more so than the men. I also quite enjoyed the more ambiguous moral compass, though I'm not sure that's a change so much as an element brought more into focus here.