Most people feel a vaporizer takes less herb than smoke. The difference in effect is 1-you drastically cut down or eliminate poisonous compounds like CO and benzene. These toxins greatly contribute to the lethargy or couchlock that's associated with the high from smoke. 2- certain cannabinoids are reported to vaporize at higher temps not usually reached with normal vaporizing. You can always crank up the temp to get the most out of your herb, but the tradeoff is a full load of toxins. Still better for ya than smoking though.