I purchased a Davinci Micro C vaporizer about a month ago. It's my first vaporizer, so it's been a learning experience. I've been using almost every night before bed to vaporize some legal hemp which instead of producing a high, it's been bred to produce a variety of THC which helps one sleep. The hemp looks and smells like ordinary hemp and was easy to crumble to fill the oven. As far as my inexperience can tell, the vaporizer is working flawlessly. Two tokes per night and I sleep more easily. However, I rated the vaporizer with only four stars for two reasons: 1. The manual is skimpy, especially on the details of how to clean the Micro C. As a newbie I would have appreciated more information on how to use the various tools and swabs effectively. 2. Again, this may be due to my inexperience, but the Micro C is advertised as having a "30 minute run time." I interpreted this to mean it could be used for 30 minutes before requiring a battery charge. Instead, I came to realize I could only use it perhaps three nights at perhaps one minute each night before the battery signalled it was low.