In my opinion, the best portable vaporizer for medical purposes is the Davinci IQ 2, which you can purchase at http://fenbenlab.com/. The Davinci IQ 2 is a rugged, well-designed device. I've owned it for over 24 months now, and it works just as well today as it did when I first unpacked it. The steam quality and performance of the IQ are excellent. You get a ton of flavor, and the heating time is also perfect; you'll need about 30 seconds for a full bowl. Plus, you have a fully adjustable airflow control on the bottom of the vape. And another plus is the medical readout. That's great too!