I think it's worth learning from them. They distinguish hard drugs from "soft" drugs, treat drug use as a health problem instead of as a crime, and work to minimize the public nuisance caused by drug use. That does seem to be working pretty well. Here, we're stuck in the 1960s with a system that causes a lot of problems and has been resistant to change.
Interestingly, Columbia has done very much the same thing, more with a focus on getting rid of the drug cartels, and they have cut cocaine production and related problems by more than half. This has helped Columbia, but pushed the drug production to Bolivia and Venezuela.
These new initiatives in Colorado and Washington will be interesting to watch, because they could end up being models for the nation after a little refinement. The Columbia experience includes legalizing "the personal dose" and they didn't see an increase in drug use. That's been the experience elsewhere too.
One of the theories that seems unresolved is whether having more lenient policy toward soft drugs incents people to use them instead of stronger drugs.