For me, the difference is quantity. Conduction vapes do a good job with the material in contact with the heat, which is usually the bottom plate of the "bowl".
Convection vapes do a good job with with the material in contact with the heat, which is usually all the the material in the bowl.
I can fully extract the same .2g of flower using a Volcano or a MFLB. The first takes 5 minutes to heat up, 1 minute to extract into a bag, and 1 minute to inhale. The second has no heat up time, but 20 minutes to extract & inhale.