I have one I use for Cannabis. No experience with using it for DMT or changa though. It's a great device for what it is. A few things to be aware of, it does not do well with oils and gummy extracts. You control the temp by inserting and removing the battery and by airflow, so it takes some getting used to and it is possible to char/burn your materials.

Get extra batteries.

If you go here you will find a ton of positive reviews.