There are lots of discussions on various forums and message board relating to which method rules.
The main difference between convection and conduction vaporizers is how they heat the herbs. Convection vapes work by streaming hot air through your plant material while exposing it directly to radiation in order break down cellular walls so that nothing stands between you and those healing properties like our favorite essential oils do when vaping them on their own. The only downside is that they require a more intense heater (think higher wattage) to heat up the air as air acts more as an insulator than a heat absorber and the hits tend to not be as thick and satisfying. Vaporizing herbs with a convection vaporizer is more efficient and produces better tasting vapors, but they tend not last as long.
Conduction vaporizers heat up the surface containing your herbs thereby heating the herbs to produce vapor. The heat from the heat source is transferred through conduction. Most vaporizers use a combination of convection and conduction heating. Conduction vaporizers, on the other hand, work because when the dry herb is in contact with a heated surface, it will vaporize which can be inhaled. In terms of vaping, both methods have their pros and cons.
Conduction herb vaporizers tend to work better with oils, waxes, and other types of substances where a convection vaporizer works best for dry herbs. When using a conduction vaporizer, one needs to load the substance in the oven or heating element where it will be heated directly or through contact.
We prefer a balanced vaporizer that uses both Convection and Conduction heating.