I have hear this from some of our members. I think it's due to the refinement process after the Co2 extraction. Some extractions are what I consider "over-refined". Look for a Co2 cartridges that are "unrefined". Or ask your dispensary to provide them. The flavor is smokey or woodsy due to the residual plant matter, but it's whole plant and that's what you would expect it to be.
The process of CO2 extraction often removes the naturally occurring terpenes of the flower to leave a less desirable taste, especially at very high concentrations of THC. That's one of the reasons we blend organically grown, therapeutic-grade essential oils in our vaporizers. This creates an enhanced entourage effect with each product, while also vastly improving the flavor of the vaporizing experience. Check us out at EvoxeLabs.com!