efficient and high is vapor by far. But a lot can be said for a "dugout" which is a little wooden box thing that is routed out to hold about 3.5 grams and a little metal ciggy thing. So you can slip it out of your pocket as you walk along, take a puff, and put it away before you let it out. No one the wiser. One hit, in public, worth a thousand pictures. But I use 3 hits to get any buzz they are small hits. Used it all the time on the Overland trains in London. Many nights I would be on the platform at Camden waiting to get over to Hackney enjoying the thing.