Outside of governing law, marijuana may not be sinful per se, but it does act as a mind altering substance (harms brain cells) and its not really possible to smoke marijuana without getting high (unlike tobacco or alcohol).
I think we have to move outside of the question as to whether something is a sin and thus be the philosopher asking, which is better? Think of the type of company that you may attract. If we are looking for how far we can push it without committing sin, then we are setting ourselves up for trouble.