Pot Smoking and Health

This NY Times well-blog article entitled "Marijuana Smoking Does Not Harm Lungs, Study Finds" describes a recent study revealing that long-term marijuana use does not harm the lungs the way that cigarette smoking does, which is contrary to the common belief about the drug. Past studies have revealed, however, that smoking pot does impair cognition. Do the benefits of smoking marijuana for chronic medical conditions outweigh the problems associated with it? How do you feel about the results of this study?