Just me, the only real difference is palm based seems to taste a little sweeter & cleaner and has a thinner consistency than soy based.
Most times during the refining processes little distinction is given to palm/coconut oil. Usually labeled palm and or coconut.
Where soy derived vg is usually labeled soy.
But, either can be accurately labeled as USP Vg with no distinction of base source.
You can tell the difference between them by taking x ml of each adding nothing but 5-7% flavoring, exactly like you would making a recipe.
Put it in a replaceable head
tank, the palm/coconut based will vape, the soy based will vape but wick much slower.
If vaped in identical conditions at the same rate the soy will give more off, odd, funky & burnt tastes.
If the two bases alone are compared side by side in an
rda ~ exact conditions, to me the palm is sweeter & cleaner, the soy heavier & musty. (?)
If put in
rda and burned on purpose the soy leaves more residue than the palm.
Me, I don't care, I can't use more than 50% vg and I don't like sweet, so whatever says USP Vg on the label works.