I kind of feel that Anderson lends himself to a film like this. He uses a lot of extreme wide angles and if you ever smoked a little dope in college the world looks a little like when you mount that 18mm on your SLR. His choice of lenses lends itself to telling the story of a guy like Doc without going over the top ala Fear and Loathing and making it a little too blatantly FX.
The humor works in best possible dry as a martini kind of way, and it's played straight like comedy should be.
But really, the premise sold me. Take a hard boiled film noir kind of mystery and replace Sam Spade with the perpetual stoner and then watch him try to solve a mystery.
It's incoherent enough to make you believe that Doc is just a little too rocked to function properly most of the time, which is reflected in his effectiveness and decision making skills. He's smart enough to not bumble his way through it, but has gotten off the magic school bus enough to do his best possible work.
And it makes the film do that one singular thing that all movies are required to do in order to be called a success... it entertains.
And honestly it's a delight to watch. The acting was great, the director was the best possible person to take on the adaptation, and the lighting walked that fine line between naturalistic and cinematic.
I'd call it a beautiful film, but it's hard to call a movie about drugs beautiful without sounding utterly pretentious... so, I'll settle with the highest praise a movie can get... it's entertaining and a pleasure to watch.