Depends on the flavor you're chasing.
Certain lighter vapes will vaporize the flavors on the surface of the plant and give you that flavor sooner, very good for sativa citrusy strains that don't cut as deep but have a lot of surface terps. These are better for low temps.
Deeper hitting convection vapes will penetrate better, and release the deeper terps in the plant.
Those very pungent, gassy strains, benefit a lot from this.
Those gassy strains tend to not have as good of flavor on the surface compared to citrus strains in my experience.
Have you ever smelled a container that smelled amazing, but the individual buds themselves on the surface didn't smell as great?
Convection vape on a higher temp with a stronger pull will hit those deep notes that are giving that built up aroma.
Ever smelled an individual bud that smelled amazing without cracking it open?
Low temp conduction vape will hit those flavors very well.
If your vape has a preheat that soaks before the first hit, such as an Arizer Solo or Crafty, those buds with deeper notes are going to last longer and do better compared to a lighter sativa.
In my experience, there will never ever be a best vape for flavor. The most important factor is how you use the vape you have.